Reaction products of sodium glucoheptonate with iron sulfate and ammonium hydroxide

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Toxicity to reproduction

To address the endpoint toxicity to reproduction, read-across on gluconates and derivatives and iron compounds was performed within the frame of a weight-of-evidence approach.The underlying hypothesis for the read-across is that glucoheptonates and gluconates, structurally similar sugar-like carbohydrate metal-complexes, share the same metabolism pathways in mammals (they are oxidized by pentose phosphate pathway) and that their possible toxicity is a function of the metal cation rather than of the gluconate or glucoheptonate anion. Based on the available information, iron glucoheptonate is not subject to classification for toxicity to reproduction and developmental effects according to European Regulation (EC) No 1272/2008.

Data on Iron salts

In a developmental and toxicity screening test according to OECD guideline 422, rats received ferrous sulfate heptahydrate orally (gavage) at doses of 0, 30, 100, 300, and 1000 mg/kg bw/day for 42 days in males or 42 - 54 days in females with treatments continuing through a 14 day pre-mating period.

The NOAEL for reproductive performance from this study was considered to be 1000 mg/kg bw/day for both parental animals and pups (SIAM, 2007). Converted to the target substance iron glucoheptonate, this corresponds to a NOAEL of 1417.6 mg FeGHA/kg bw/day. The same study was performed with ferric chloride at doses of 0, 125, 250 and 500 mg/kg bw/day. A NOAEL of 500 mg/kg bw/day was obtained, based on no significant difference in mating data and pre-and post-implantation loss rate (SIAM, 2007). Converted to FeGHA, this corresponds to a NOAEL of 1204.95 mg/kg bw/day.

Data on gluconates and derivatives

No reproduction toxicity study was available for any of the gluconates of the category. However, negative results in the histopathology of the reproductive organs in repeated dose studies on sodium gluconate and negative data on the teratogenicity of glucono-delta-lactone (Food & Drug Laboratories, 1973) support the lack of reproductive toxicity for all the gluconates of the category. On the basis of these data showing a lack of toxicity and considering that gluconates have been recognized direct food additives, no further tests are considered necessary.

The repeated dose studies of sodium gluconate were in detail:

A 28-day study was conducted by feeding rats by gavage with sodium gluconate at doses of 0, 500, 1000, 2000 mg/kg bw/day in water at a volume of 1 mL/ 100g bw.No deaths or clinical signs of abnormality were observed in any of the groups. Histopathological examination showed a thickening of the limiting ridge of the stomach in 5 out of 12 males at 2000 mg/kg bw/day dose. No toxic changes associated with the test article were detected. As the limiting ridge is a tissue specific to rodents, this lesion is not toxicologically relevant for humans. Other lesions occurred incidentally and were not treatment -related. The NOAEL was estimated to be 1000 mg/kg bw/day for males and 2000 mg/kg bw/day for female (Mochizuki, M, Bozo Research Center, 1995a).

A 28-day oral feeding study was conducted. Rats were fed with a diet containing 5 % sodium gluconate at doses of 0, 1000, 2000 and 4100 mg/kg bw/day (max. 4100 mg/kg bw/day for males and 4400 mg/kg bw/day for females). A control group received equivalent concentration of sodium in the form of NaCl in order to differentiate the potential effects of high doses of sodium intake.No deaths occurred during the study period. No revisions in the general condition, body weight, or food and water intake were observed in the animals over the study period. No changes were observed in the investigated ophthamologic tests, urinalysis, hematology and blood chemistry over the study period. In addition, histopathological examination indicated no adverse effects as a result of the treatment regime. Statistically significant differences in some urinary parameters reported in animals receiving 2.5 or 5 % sodium gluconate were comparable to those observed in the NaCl control group, and were interpreted as related to the high sodium concentration of the diet.The authors concluded that the NOAEL was 5% (equal to 4100 mg/kg bw/day). However, the JECFA committee who evaluated this report has concluded that the study was not suitable for identifying a NOAEL because of the small group sizes and the positive findings in the qualitative analysis, even if they have acknowledged that the effects shown in the qualitative urine analyses were related to the high sodium intake (Mochizuki, M. Bozo Research Center, 1997). Nonetheless, this study demonstrates the lack of effects of the gluconate anion even in large doses as the urinary effects were attributed to the high sodium intake and was therefore considered as critical for this endpoint.

Repeated toxicity studies in Beagle dogs were conducted with sodium gluconate administered orally for 4 weeks at 500, 1000, 2000 mg/kg bw/day doses.None of the animals died during the period of treatment in any dose group and no significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination. However, increased frequency of vomiting and loose or watery stools was observed in the 1000 and 2000 mg/kg bw/day dose groups, as compared to controls. On the basis of these results, the non-toxic dose was estimated to be 500 mg/kg bw/ day. However, the toxicological effects observed (vomiting, passage of loose or waters stools) were considered extremely slight since other tests did not show the same changes (Okamoto, M. Bozo Research Center, 1995a).

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Conclusion

As evident from the results of the available studies, deviations from normal reproductive performance/fertility in treated animals as well as impaired developmental and post natal findings occur only at the dose levels of maternal toxicity and therefore they are considered as a consequence of this systemic toxicity.

Link to relevant study records

Reference

Reference 1

Endpoint:

one-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to reproductive toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No drug related mortality.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group.
Body weights by Day 18 of gestation were significantly decreased compared with controls.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation.

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar.

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar.

The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. Fetal weights were significantly (P<0.01) reduced in the 100 mg/kg group.
There were no drug induced malformations seen in this study.
The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

Dose descriptor:

NOAEL

Effect level:

ca. 30 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

food efficiency

gross pathology

reproductive performance

Dose descriptor:

NOAEL

Effect level:

ca. 212.64 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

food efficiency

gross pathology

reproductive performance

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

No drug related mortality. Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group. The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group. Body weights by Day 18 of gestation were significantly decreased compared with controls. Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation. Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice. The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar. Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group. There were no drug induced malformations seen in this study. The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant mice from gestation day 6 to 15 (sanofi-aventis Canada Inc. 2009). The employed doses were 10, 30 and 100 mg Fe /kg bw. No drug related mortality was observed. Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group. The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group. Body weights by Day 18 of gestation were significantly decreased compared with controls. Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation. Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice. The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar. Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group. There were no drug induced malformations seen in this study. The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

A NOAEL of 212.64 mg FeGHA/kg can be established for maternal toxicity of the target substance iron glucoheptonate.

Reference 2

Endpoint:

one-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to reproductive toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No treatment-related deaths

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Body weights and food consumption for the treated groups were comparable to the controls

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Body weights and food consumption for the treated groups were comparable to the controls

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Dose descriptor:

NOAEL

Effect level:

> 30 other: mg Fe/kg

Based on:

element

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

NOAEL

Effect level:

> 212.64 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks on result:

not measured/tested

Reproductive effects observed:

no

No treatment-related deaths. Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control. Body weights and food consumption for the treated groups were comparable to the controls. No gross pathological findings. The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were similar to control values. The incidence of major malformations and minor anomalies was unaffected.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant mice from gestation day 6 to 15 (sanofi-aventis Canada Inc. 2009). The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw. No treatment-related deaths were observed. Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control. Body weights and food consumption for the treated groups were comparable to the controls. No gross pathological findings. The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were similar to control values. The incidence of major malformations and minor anomalies was unaffected.

A NOAEL of > 212.64 mg FeGHA/kg bw can be established for the target substance iron glucoheptonate.

Reference 3

Endpoint:

one-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to reproductive toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.
There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera. The fetuses were similar in number and weight to those from the animals treated with vehicle.

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.
There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera. The fetuses were similar in number and weight to those from the animals treated with vehicle.

Dose descriptor:

NOAEL

Effect level:

> 1.875 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

mortality

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

NOAEL

Effect level:

> 13.29 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

mortality

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera.

The fetuses were similar in number and weight to those from the animals treated with vehicle.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant rabbits from gestation day 1 to 23 and 28. The employed dose was 1.875 mg Fe /kg bw. IV injections of Ferrlecit® at 1.875 mg Fe/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses. There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera. The fetuses were similar in number and weight to those from the animals treated with vehicle.

A NOAEL of > 13.29 mg FeGHA/kg bw can be established here for maternal toxicity of the target substance iron glucoheptonate.

Reference 4

Endpoint:

one-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to reproductive toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weakness, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/Day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally.

Dose descriptor:

NOAEL

Effect level:

ca. 5 mg/kg bw/day

Based on:

element

Sex:

not specified

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Dose descriptor:

NOAEL

Effect level:

ca. 35.44 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study. Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weak, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above. Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18. Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/Day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively. Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups. The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant rats from gestation day 6 to 17 (sanofi-aventis Canada Inc., 2009). The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw. Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study. Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weakness, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above. Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18. Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively. Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups. The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally. Converted to the target substance iron glucoheptonate a NOAEL of 5 mg Fe/kg bw corresponds to a value of 35.44 mg/kg bw/day.

Reference 5

Endpoint:

two-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to reproductive toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No deaths, and no animals were sacrificed in poor condition during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Dose descriptor:

NOAEL

Effect level:

ca. 1 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Dose descriptor:

NOAEL

Effect level:

ca. 7.09 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Critical effects observed:

no

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Description (incidence):

The viability and survival indices were unaffected. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains.

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

no effects observed

Description (incidence and severity):

The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Reproductive performance:

no effects observed

Description (incidence and severity):

The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Dose descriptor:

NOAEL

Effect level:

ca. 1 mg/kg bw/day

Based on:

element

Sex:

male/female

Basis for effect level:

mortality

body weight and weight gain

reproductive performance

Dose descriptor:

NOAEL

Effect level:

7.09 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

mortality

body weight and weight gain

reproductive performance

Remarks on result:

not measured/tested

Clinical signs:

no effects observed

Description (incidence and severity):

The reproductive capacity of the F1 generation was not affected and their offspring (F2) were normal with respect to clinical observations and weight gains.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

The reproductive capacity of the F1 generation was not affected and their offspring (F2) were normal with respect to clinical observations and weight gains.

Reproductive effects observed:

no

F0 Generation: No deaths, and no animals were sacrificed in poor condition during the study. Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group. There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg. Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group. There were no treatment-related gross pathological changes. Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

F1 Generation: The viability and survival indices were unaffected. There were no treatment-related clinical findings. Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant rats from gestation day 6 to 17 and throughout postpartum day 21. The employed doses were 1, 5 and 10 mg Fe /kg bw.

F0 Generation: No deaths, and no animals were sacrificed in poor condition during the study. Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group. There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg. Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group. There were no treatment-related gross pathological changes. Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

F1 Generation: The viability and survival indices were unaffected. There were no treatment-related clinical findings. Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

A NOAEL of 1.0 mg Fe/kgcan be established here for maternal toxicity. This corresponds to a NOAEL of 7.09 mg/kg bw/dayof the traget substance iron glucoheptonate

Reference 6

Endpoint:

one-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to reproductive toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality.
Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality.
Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

no effects observed

Description (incidence and severity):

Both treatment groups consumed more water than the controls, but a significant difference was not observed.

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Dose descriptor:

NOAEL

Effect level:

4 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

mortality

body weight and weight gain

food consumption and compound intake

water consumption and compound intake

gross pathology

reproductive performance

Dose descriptor:

NOAEL

Effect level:

28.35 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

mortality

body weight and weight gain

food consumption and compound intake

water consumption and compound intake

gross pathology

reproductive performance

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality / viability:

not specified

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There was no difference in the litter size or birth weights between the controls and 4 mg/kg group.
There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

No treatment related anomalies were observed.
However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Histopathological findings:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

ca. 4 mg/kg bw/day

Based on:

element

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

Remarks on result:

other: There was no evidence of teratogenicity at any dose level.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

ca. 20 mg/kg bw/day

Based on:

element

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

Remarks on result:

other: There was no evidence of teratogenicity at any dose level.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

28.35 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

Remarks on result:

other: There was no evidence of teratogenicity at any dose level.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

141.76 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

Remarks on result:

other: There was no evidence of teratogenicity at any dose level.

Reproductive effects observed:

no

Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality. Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake. Both treatment groups consumed more water than the controls, but a significant difference was not observed. The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant rats from gestation day 6 to 15 (sanofi-aventis Canada Inc., 2009). The employed doses were 4 and 20 mg Fe /kg bw. Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality. Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake. Both treatment groups consumed more water than the controls, but a significant difference was not observed. The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Converted to the target substance iron glucoheptonate, this means that no teratogenic effects are expected as a dose of 141.76 mg FeGHA/kg bw/day. The NOAEL for maternal toxicity is > 28.35 mg FeGHA/kg bw/day

Reference 7

Endpoint:

reproductive toxicity, other

Remarks:

results of the histopathology and pathology examinations of a repeated dose study (4-weeks, oral gavage) in rats

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to toxicity to reproduction after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: Gluconates and derivatives

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Sodium D-gluconate CAS 527-07-1
SMILES: [Na+].[O-]C(=O)[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO
MW 218.14 g/mol
The molecular formula is C6H11NaO7
Purity (%) of Sodium gluconate: 98-102% (OECD SIDS, 2004)

Glucono-delta-lactone, sodium gluconate and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than of the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their toxicity to the reproductive system, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the reproductive organs (histopathological examinations found no alternations) of rats and dogs or on development of pups of rats, mice, hamsters and rabbits.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Reproductive indices:

not examined

Offspring viability indices:

not examined

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Histopathological examination showed a thickening of the limiting ridge of the stomach in 5 out of 12 males at 2000 mg/kg bw per day dose. No toxic changes associated with the test article were detected. As the limiting ridge is a tissue specific to rodents, this lesion is not toxicologically relevant for humans. Other lesions occurred incidentally and were not treatment-related.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not specified

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

A 28-day study was conducted by feeding rats by gavage with sodium gluconate at doses of 0, 500, 1000, 2000 mg/kg bw in water at a volume of 1 mL/100g bw. No death or clinical signs of abnormality were observed in any of the groups. Histopathological examination showed a thickening of the limiting ridge of the stomach in 5 out of 12 males at 2000 mg/kg bw per day dose. No toxic changes associated with the test article were detected. As the limiting ridge is a tissue specific to rodents, this lesion is not toxicologically relevant for humans. Other lesions occurred incidentally and were not treatment -related.
The NOAEL was estimated to be 1000 mg/kg bw/day for males and 2000 mg/kg bw/day for female (Mochizuki, M, Bozo Research Center, 1995a).

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

sodium gluconate

Sex:

male

Basis for effect level:

clinical signs

mortality

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

Dose descriptor:

NOAEL

Effect level:

2 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Sodium gluconate

Sex:

female

Basis for effect level:

clinical signs

mortality

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

Remarks on result:

not measured/tested

Reproductive effects observed:

no

A 28-day study was conducted by feeding rats by gavage with sodium gluconate at doses of 0, 500, 1000, 2000 mg/kg bw in water at a volume of 1 mL/ 100g bw. No death or clinical signs of abnormality were observed in any of the groups. Histopathological examination showed a thickening of the limiting ridge of the stomach in 5 out of 12 males at 2000 mg/kg bw per day dose. No toxic changes associated with the test article were detected. As the limiting ridge is a tissue specific to rodents, this lesion is not toxicologically relevant for humans. Other lesions occurred incidentally and were not treatment -related. The NOAEL was estimated to be 1000 mg/kg bw/day for males and 2000 mg/kg bw/day for female (Mochizuki, M, Bozo Research Center, 1995a).

Conclusions:

SIDS testing requirements regarding reproductive toxicity were satisfied with histopathology of the reproductive organs in repeat dose studies on sodium gluconate and with developmental toxicity studies on glucono-delta-lactone.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Executive summary:

No reproduction toxicity study was available for any of the gluconates of the category. However, negative results in the histopathology of the reproductive organs in repeat dose studies on sodium gluconate and negative data on the teratogenicity of glucono-delta-lactone (Food & Drug Laboratories, 1973) support the lack of reproductive toxicity for all the gluconates of the category. On the basis of these data showing a lack of toxicity and considering that gluconates have been recognized direct food additives, no further tests are considered necessary.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Reference 8

Endpoint:

reproductive toxicity, other

Remarks:

results of the histopathology and pathology examinations of a repeated dose study (4-weeks, oral feed) in rats

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to toxicity to reproduction after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: Gluconates and derivatives

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Sodium D-gluconate CAS 527-07-1
SMILES: [Na+].[O-]C(=O)[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO
MW 218.14 g/mol
The molecular formula is C6H11NaO7
Purity (%) of Sodium gluconate: 98-102% (OECD SIDS, 2004)

Glucono-delta-lactone, sodium gluconate and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than of the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their toxicity to the reproductive system, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the reproductive organs (histopathological examinations found no alternations) of rats and dogs or on development of pups of rats, mice, hamsters and rabbits.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

no effects observed

Description (incidence and severity):

No revisions in the general condition.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No deaths occurred during the study period.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No revisions in the body weight, or food and water intake were observed in the animals over the study period.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

No revisions in the body weight, or food and water intake were observed in the animals over the study period.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Description (incidence and severity):

No revisions in the body weight, or food and water intake were observed in the animals over the study period.

Ophthalmological findings:

no effects observed

Description (incidence and severity):

No changes were observed in the investigated ophthalmologic tests, urinalysis, hematology and blood chemistry over the study period.

Haematological findings:

no effects observed

Description (incidence and severity):

No changes were observed in the investigated ophthalmologic tests, urinalysis, hematology and blood chemistry over the study period.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

No changes were observed in the investigated ophthalmologic tests, urinalysis, hematology and blood chemistry over the study period.

Urinalysis findings:

no effects observed

Description (incidence and severity):

No changes were observed in the investigated ophthalmologic tests, urinalysis, hematology and blood chemistry over the study period. Statistically significant differences in some urinary parameters reported in animals receiving 2.5 or 5% sodium gluconate were comparable to those observed in the NaCl control group, and were interpreted as related to the high sodium concentration of the diet.

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

In addition, histopathological examination indicated no adverse effects as a result of the treatment regime.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not specified

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Another 28-day toxicity study in rats fed with a diet containing up to 5% w/w sodium gluconate (max. 4100 mg/kg bw for males and 4400 mg/kg bw for females) was conducted using a control group receiving equivalent concentration of sodium in the form of NaCl in order to differentiate the potential effects of high doses of sodium intake. No deaths occurred during the study period. No revisions in the general condition, body weight, or food and water intake were observed in the animals over the study period. No changes were observed in the investigated ophthalmologic tests, urinalysis, hematology and blood chemistry over the study period. In addition, histopathological examination indicated no adverse effects as a result of the treatment regime. Statistically significant differences in some urinary parameters reported in animals receiving 2.5 or 5% sodium gluconate were comparable to those observed in the NaCl control group, and were interpreted as related to the high sodium concentration of the diet.
The authors concluded that the NOAEL was 5% (equal to 4100 mg/kg bw per day). However, The JECFA committee who evaluated this report has concluded that the study was not suitable for identifying a NOAEL because of the small group sizes and the positive findings in the qualitative analysis, even if they have acknowledged that the effects shown in the qualitative urine analyses were related to the high sodium intake (Mochizuki, M. Bozo Research Center, 1997). Nonetheless, this study demonstrates the lack of effects of the gluconate anion even in large doses as the urinary effects were attributed to the high sodium intake and was therefore considered as critical for this endpoint.

Dose descriptor:

NOAEL

Effect level:

4 100 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Sodium gluconate

Sex:

male/female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

water consumption and compound intake

ophthalmological examination

haematology

clinical biochemistry

urinalysis

organ weights and organ / body weight ratios

gross pathology

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Another 28-day toxicity study in rats fed with a diet containing up to 5% w/w sodium gluconate (max. 4100 mg/kg bw for males and 4400 mg/kg bw for females) was conducted using a control group receiving equivalent concentration of sodium in the form of NaCl in order to differentiate the potential effects of high doses of sodium intake. No deaths occurred during the study period. No revisions in the general condition, body weight, or food and water intake were observed in the animals over the study period. No changes were observed in the investigated ophthalmologic tests, urinalysis, hematology and blood chemistry over the study period. In addition, histopathological examination indicated no adverse effects as a result of the treatment regime. Statistically significant differences in some urinary parameters reported in animals receiving 2.5 or 5% sodium gluconate were comparable to those observed in the NaCl control group, and were interpreted as related to the high sodium concentration of the diet.

The authors concluded that the NOAEL was 5% (equal to 4100 mg/kg bw per day). However, The JECFA committee who evaluated this report has concluded that the study was not suitable for identifying a NOAEL because of the small group sizes and the positive findings in the qualitative analysis, even if they have acknowledged that the effects shown in the qualitative urine analyses were related to the high sodium intake (Mochizuki, M. Bozo Research Center, 1997). Nonetheless, this study demonstrates the lack of effects of the gluconate anion even in large doses as the urinary effects were attributed to the high sodium intake and was therefore considered as critical for this endpoint.

Conclusions:

SIDS testing requirements regarding reproductive toxicity were satisfied with histopathology of the reproductive organs in repeat dose studies on sodium gluconate and with developmental toxicity studies on glucono-delta-lactone.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Executive summary:

No reproduction toxicity study was available for any of the gluconates of the category. However, negative results in the histopathology of the reproductive organs in repeat dose studies on sodium gluconate and negative data on the teratogenicity of glucono-delta-lactone (Food & Drug Laboratories, 1973) support the lack of reproductive toxicity for all the gluconates of the category. On the basis of these data showing a lack of toxicity and considering that gluconates have been recognized direct food additives, no further tests are considered necessary.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Reference 9

Endpoint:

reproductive toxicity, other

Remarks:

results of the histopathology and pathology examinations of a repeated dose study (4-weeks, oral feed) in dogs

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to toxicity to reproduction after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: Gluconates and derivatives

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Sodium D-gluconate CAS 527-07-1
SMILES: [Na+].[O-]C(=O)[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO
MW 218.14 g/mol
The molecular formula is C6H11NaO7
Purity (%) of Sodium gluconate: 98-102% (OECD SIDS, 2004)

Glucono-delta-lactone, sodium gluconate and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than of the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their toxicity to the reproductive system, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the reproductive organs (histopathological examinations found no alternations) of rats and dogs or on development of pups of rats, mice, hamsters and rabbits.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Increased frequency of vomiting and loose or watery stools were observed in the 1000 and 2000 mg/kg bw dose groups, as compared to controls.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

None of the animals died during the period of treatment in any dose group.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination. However, increased frequency of vomiting and loose or watery stools were observed in the 1000 and 2000 mg/kg bw dose groups, as compared to controls.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Ophthalmological findings:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Haematological findings:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Urinalysis findings:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

No significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination.

Other effects:

not specified

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Repeated toxicity studies were also performed on Beagle dogs with sodium gluconate administered orally for 4 weeks at 500, 1000, 2000 mg/kg bw doses. None of the animals died during the period of treatment in any dose group and no significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination. However, increased frequency of vomiting and loose or watery stools were observed in the 1000 and 2000 mg/kg bw dose groups, as compared to controls.
On the basis of these results, the non-toxic dose was estimated to be 500 mg/kg bw/day. However, the toxicological effects observed (vomiting, passage of loose or watery stools) were considered extremely slight since other tests did not show the same changes (Okamoto, M. Bozo Research Center, 1995a).

Remarks on result:

not determinable due to absence of adverse toxic effects

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Repeated toxicity studies were also performed on Beagle dogs with sodium gluconate administered orally for 4 weeks at 500, 1000, 2000 mg/kg bw doses. None of the animals died during the period of treatment in any dose group and no significantly toxicologically changes were detected in the body weight, food intake, water intake, urinalysis, haematological test, blood chemistry analysis, ophthalmologic test, electrocardiography, autopsy and organ weight or in histopathological examination. However, increased frequency of vomiting and loose or watery stools were observed in the 1000 and 2000 mg/kg bw dose groups, as compared to controls.

On the basis of these results, the non-toxic dose was estimated to be 500 mg/kg bw/day. However, the toxicological effects observed (vomiting, passage of loose or watery stools) were considered extremely slight since other tests did not show the same changes (Okamoto, M. Bozo Research Center, 1995a).

Conclusions:

SIDS testing requirements regarding reproductive toxicity were satisfied with histopathology of the reproductive organs in repeated dose studies on sodium gluconate and with developmental toxicity studies on glucono-delta-lactone.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Executive summary:

No reproduction toxicity study was available for any of the gluconates of the category. However, negative results in the histopathology of the reproductive organs in repeated dose studies on sodium gluconate and negative data on the teratogenicity of glucono-delta-lactone (Food & Drug Laboratories, 1973) support the lack of reproductive toxicity for all the gluconates of the category. On the basis of these data showing a lack of toxicity and considering that gluconates have been recognized direct food additives, no further tests are considered necessary.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that sodium gluconate is not toxic after repeated oral intake and the fact that it does not provoque any effects on the reproductive system is important.

Reference 10

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

other: review article

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: public report

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

not specified

GLP compliance:

not specified

Species:

rat

Sex:

male/female

Route of administration:

oral: gavage

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

42 days in males or 42 - 54 days in females with treatments continuing through a 14 day pre-mating period

Dose / conc.:

125 mg/kg bw/day

Dose / conc.:

250 mg/kg bw/day

Dose / conc.:

500 mg/kg bw/day

Control animals:

yes

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

Dose descriptor:

NOAEL

Remarks:

iron chloride

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: mating data and pre-and post-implantation loss rate

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Executive summary:

In an OECD 422 study rats received 0, 125, 250 and 500 mg/kg/day of ferric chloride by the oral route (gavage) for 42 days in males or 42 - 54 days in females with treatments continuing through a 14 day pre-mating period. A NOAEL of 500 mg/kg body weight/day was obtained, based on no significant difference in mating data and pre-and post-implantation loss rate.

Reference 11

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

other: public report

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: reliable public report

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

not specified

GLP compliance:

not specified

Species:

rat

Strain:

not specified

Sex:

not specified

Route of administration:

oral: unspecified

Dose / conc.:

30 mg/kg bw/day

Dose / conc.:

100 mg/kg bw/day

Dose / conc.:

300 mg/kg bw/day

Dose / conc.:

1 000 mg/kg bw/day

Control animals:

yes

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

reproductive performance

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Executive summary:

In an OECD 422 study rats received ferrous sulfate heptahydrate orally at doses of 0, 30, 100, 300, and 1000 mg/kg/day. The NOAEL for reproductive performance from this study was considered to be 1000 mg/kg/day for both parental animals and pups.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 204.95 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The quality of the whole database is considered sufficient for estimation of reproductive toxicity potential, because of the multipicity of available data for the different read-across substances.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Data on sodium ferric gluconate complex in sucrose injection

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant rats from gestation day 6 to 17 (sanofi-aventis Canada Inc., 2009). The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw/day. Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study. Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weakness, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above. Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18. Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg bw/day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively. Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups. The pregnancy rate was at least 83 % in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment. Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally.

A NOAEL of 5.0 mg Fe/kg bw/day can be established here for maternal toxicity. This corresponds to a NOAEL of 35.44 mg iron glucoheptonate/kg bw/day.

In another study rats received Ferrlecit from gestation day 6 to 17 and throughout postpartum day 21 (sanofi-aventis Canada Inc., 2009). The employed doses were 1, 5 and 10 mg Fe /kg bw/da. In the F0 Generation no deaths were observed, and no animals were sacrificed in poor condition during the study. Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group. There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg. Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group. There were no treatment-related gross pathological changes. Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment. In the F1 Generation, the viability and survival indices were unaffected. There were no treatment-related clinical findings. Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

A NOAEL of 1.0 mg Fe/kg bw/day can be established here for maternal toxicity. This corresponds to a NOAEL of 7.09 mg iron glucoheptonate/kg bw/day.

In addition, Ferrlecit was adminstered to pregnant rats from gestation day 6 to 15 (sanofi-aventis Canada Inc., 2009). The employed doses were 4 and 20 mg Fe /kg bw/day. Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality. Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake. Both treatment groups consumed more water than the controls, but a significant difference was not observed. The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

A NOAEL of 4.0 mg Fe/kg bw/day can be established here for maternal toxicity. This corresponds to a NOAEL of 28.35 mg iron glucoheptonate/kg bw/day.

Additionally, Ferrlecit was adminstered to pregnant mice from gestation day 6 to 15. The employed doses were 10, 30 and 100 mg Fe /kg bw/day. No drug related mortality was observed. Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group. The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group. Body weights by Day 18 of gestation were significantly decreased compared with controls. Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation. Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice. The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar. Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group. There were no drug induced malformations seen in this study. The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

A NOAEL of 30.0 mg Fe/kg bw/day can be established here for maternal toxicity. This corresponds to a NOAEL of 212.64 mg iron glucoheptonate/kg bw/day.

Moreover, Ferrlecit was adminstered to pregnant mice from gestation day 6 to 15. The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw/day. No treatment-related deaths were observed. Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control. Body weights and food consumption for the treated groups were comparable to the controls. No gross pathological findings were recorded. The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were similar to control values. The incidence of major malformations and minor anomalies was unaffected.

A NOAEL of > 30.0 mg Fe/kg bw/day can be established here for maternal toxicity. This corresponds to a NOAEL of > 212.64 mg iron glucoheptonate/kg bw/day.

In conclusion, FERRLECIT (sodium ferric gluconate complex in sucrose injection) was not teratogenic at doses of elemental iron up to 100 mg/kg bw/day (300 mg/m²/day) in mice and 20 mg/kg bw/day (120 mg/m²/day) in rats. On a body surface area basis, these doses were 1.3 and 3.24 times the recommended human dose (125 mg/day or 92.5 mg/m²/day) for a person of 50 kg body weight, average height and body surface area of 1.46 m².

Finally, Ferrlecit was adminstered to pregnant rabbits from gestation day 1 to 23 and 28. The employed dose was 1.875 mg Fe /kg bw. 1.875 mg/kg bw/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses. There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera. The fetuses were similar in number and weight to those from the animals treated with vehicle.FERRLECIT (sodium ferric gluconate complex in sucrose injection) was not teratogenic at doses of elemental iron of 1.875 mg/kg/day in rabbits. Thus, a NOAEL of > 1.875 mg Fe/kg can be established here for maternal toxicity. This corresponds to a NOAEL of > 13.29 mg iron glucoheptonate/kg bw/day.

In conclusion, FERRLECIT (sodium ferric gluconate complex in sucrose injection) was not teratogenic at doses of elemental iron of 1.875 mg/kg/day in rabbits.

Effects on developmental toxicity

Description of key information

Developmental toxicity

To address the endpoint developmental toxicity read-across on gluconates and derivatives and iron compounds was performed within the frame of a weight-of-evidence approach.The underlying hypothesis for the read-across is that glucoheptonates and gluconates, structurally similar sugar-like carbohydrate metal-complexes, share the same metabolism pathways in mammals (they are oxidized by pentose phosphate pathway) and that their possible toxicity is a function of the metal cation rather than of the gluconate or glucoheptonate anion.

Data on iron salts

The relevant maternal and developmental toxicity NOAELs in a screening study for reproductive and developmental toxicity were 380 mg/kg bw/day iron sulfate in both rats and mice (reduced body weight in dams, increased implantation loss at 1200 mg/kg bw/day) (EFSA, 2012). Converted to the target substance iron glucoheptonate, this corresponds to a NOAEL of 996.56 mg FeGHA/kg bw/day and an effect concentration of > 3147.04 mg/kg bw/day.

Conclusion 

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, no teratogenicity can be attributed to the glucoheptonate moiety of iron glucoheptonate

 

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to developmental toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

reference to same study

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No drug related mortality.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group.
Body weights by Day 18 of gestation were significantly decreased compared with controls.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation.

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Number of abortions:

no effects observed

Description (incidence and severity):

The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar.

Total litter losses by resorption:

effects observed, treatment-related

Description (incidence and severity):

Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality.

Early or late resorptions:

effects observed, treatment-related

Description (incidence and severity):

The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality.

Dead fetuses:

no effects observed

Description (incidence and severity):

The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar.

Dose descriptor:

NOAEL

Effect level:

ca. 30 other: mg Fe/kg

Based on:

element

Basis for effect level:

body weight and weight gain

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

food efficiency

gross pathology

mortality

pre and post implantation loss

total litter losses by resorption

Dose descriptor:

NOAEL

Effect level:

ca. 212.64 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

food efficiency

gross pathology

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

Fetal weights were significantly (P<0.01) reduced in the 100 mg/kg group.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): effects observed, treatment-related
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group.

Reduction in number of live offspring:

not specified

Changes in sex ratio:

no effects observed

Description (incidence and severity):

The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar.

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

There were no drug induced malformations seen in this study.
The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

Skeletal malformations:

no effects observed

Description (incidence and severity):

There were no drug induced malformations seen in this study.
The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

Visceral malformations:

no effects observed

Description (incidence and severity):

There were no drug induced malformations seen in this study.
The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

ca. 30 other: mg Fe/kg

Based on:

element

Sex:

male/female

Basis for effect level:

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Dose descriptor:

NOAEL

Effect level:

ca. 212.64 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Developmental effects observed:

no

No drug related mortality. Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group. The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group. Body weights by Day 18 of gestation were significantly decreased compared with controls. Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation. Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice. The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar. Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group. There were no drug induced malformations seen in this study. The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant mice from gestation day 6 to 15 (sanofi-aventis Canada Inc., 2009). The employed doses were 10, 30 and 100 mg Fe /kg bw. No drug related mortality. Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group. The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group. Body weights by Day 18 of gestation were significantly decreased compared with controls. Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation. Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice. The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar. Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group. There were no drug induced malformations seen in this study. The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

A NOAEL of 30.0 mg Fe/kg can be established here for maternal and developmental toxicity. This corresponds to a NOAEL of 212.64 mg/kg bw/day of the target substance iron glucoheptonate.

Reference 2

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to developmental toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No treatment-related deaths

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Body weights and food consumption for the treated groups were comparable to the controls

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Body weights and food consumption for the treated groups were comparable to the controls

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

No gross pathological findings.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Number of abortions:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Early or late resorptions:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Dead fetuses:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Other effects:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Dose descriptor:

NOAEL

Effect level:

> 30 other: mg Fe/kg

Based on:

element

Basis for effect level:

body weight and weight gain

changes in number of pregnant

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

gross pathology

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

NOAEL

Effect level:

> 212.64 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

changes in number of pregnant

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

gross pathology

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Remarks on result:

not determinable due to absence of adverse toxic effects

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Fetal weights were similar to control values.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Fetal weights were similar to control values.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment.

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

The incidence of major malformations and minor anomalies was unaffected.

Skeletal malformations:

no effects observed

Description (incidence and severity):

The incidence of major malformations and minor anomalies was unaffected.

Visceral malformations:

no effects observed

Description (incidence and severity):

The incidence of major malformations and minor anomalies was unaffected.

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 30 other: mg Fe/kg

Based on:

element

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

NOAEL

Effect level:

> 212.64

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Remarks on result:

not determinable due to absence of adverse toxic effects

Developmental effects observed:

no

No treatment-related deaths. Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control. Body weights and food consumption for the treated groups were comparable to the controls. No gross pathological findings. The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were similar to control values. The incidence of major malformations and minor anomalies was unaffected.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant mice from gestation day 6 to 15 (sanofi-aventis Canada Inc., 2009). The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw. No treatment-related deaths. Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control. Body weights and food consumption for the treated groups were comparable to the controls. No gross pathological findings. The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were similar to control values. The incidence of major malformations and minor anomalies was unaffected.

A NOAEL of > 30.0 mg Fe/kg can be established here for maternal and developmental toxicity. This corresponds to a NOAEL of > 212.64 mg FeGHA/kg bw.

Reference 3

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to developmental toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Number of abortions:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Early or late resorptions:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Dead fetuses:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Other effects:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

Dose descriptor:

NOAEL

Effect level:

> 1.875 other: mg Fe/kg

Based on:

element

Basis for effect level:

changes in number of pregnant

dead fetuses

early or late resorptions

number of abortions

pre and post implantation loss

total litter losses by resorption

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

NOAEL

Effect level:

> 13.29 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

changes in number of pregnant

dead fetuses

early or late resorptions

number of abortions

pre and post implantation loss

total litter losses by resorption

Remarks on result:

not determinable due to absence of adverse toxic effects

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.
The fetuses were similar in number and weight to those from the animals treated with vehicle.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.
The fetuses were similar in number and weight to those from the animals treated with vehicle.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.
The fetuses were similar in number and weight to those from the animals treated with vehicle.

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.
The fetuses were similar in number and weight to those from the animals treated with vehicle.

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera.

Skeletal malformations:

no effects observed

Description (incidence and severity):

There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera.

Visceral malformations:

no effects observed

Description (incidence and severity):

There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera.

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 1.875 mg/kg bw/day

Based on:

element

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in litter size and weights

external malformations

skeletal malformations

visceral malformations

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

NOAEL

Effect level:

> 13.29 mg/kg bw/day

Based on:

test mat.

Remarks:

iron glucoheptonate

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in litter size and weights

external malformations

skeletal malformations

visceral malformations

Remarks on result:

not determinable due to absence of adverse toxic effects

Developmental effects observed:

no

IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses.

There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera.

The fetuses were similar in number and weight to those from the animals treated with vehicle.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant rabbits from gestation day 1 to 23 and 28. The employed dose was 1.875 mg Fe /kg bw. IV injections of Ferrlecit® at 1.875 mg/kg/day in pregnant rabbits did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses. There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera. The fetuses were similar in number and weight to those from the animals treated with vehicle.

A NOAEL of > 1.875 mg Fe/kg can be established here for maternal and developmental toxicity. This corresponds to a NOAEL of > 13.29 mg/kg bw/day of the target substance iron glucoheptonate.

Reference 4

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to developmental toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

reference to same study

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weak, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/Day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Sacrificed animals:
Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder.

Animals examined at cesarean section:
Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Number of abortions:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Early or late resorptions:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Dead fetuses:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Other effects:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Dose descriptor:

NOAEL

Effect level:

ca. 5 other: mg Fe/kg

Based on:

element

Basis for effect level:

body weight and weight gain

changes in number of pregnant

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

gross pathology

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Dose descriptor:

NOAEL

Effect level:

ca. 35.44 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

changes in number of pregnant

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

gross pathology

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

Fetal weights were slightly reduced in the 15 and 30 mg/kg groups.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): effects observed, treatment-related
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Fetal weights were slightly reduced in the 15 and 30 mg/kg groups.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment.

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

There were no major malformations or minor anomalies observed externally.

Skeletal malformations:

no effects observed

Description (incidence and severity):

There were no major malformations or minor anomalies observed externally.

Visceral malformations:

no effects observed

Description (incidence and severity):

There were no major malformations or minor anomalies observed externally.

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

ca. 5 other: mg Fe/kg

Based on:

element

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Dose descriptor:

NOAEL

Effect level:

ca. 35.44 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Developmental effects observed:

no

Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study. Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weak, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above. Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18. Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/Day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively. Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups. The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant rats from gestation day 6 to 17 (sanofi-aventis Canada Inc., 2009). The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw. Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study. Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weak, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above. Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18. Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/Day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively. Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups. The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment. Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally.

Converted to the target substance iron glucoheptonate a NOAEL of 5 mg Fe/kg bw corresponds to a value of 35.44 mg/kg bw/day.

Reference 5

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to developmental toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

reference to same study

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No deaths, and no animals were sacrificed in poor condition during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

There were no treatment-related gross pathological changes.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Details on results:

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Number of abortions:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Early or late resorptions:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Dead fetuses:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.DescriptionIncidenceAndSeverityEffectsOnPregnancyDuration): Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Other effects:

no effects observed

Description (incidence and severity):

Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

Dose descriptor:

NOAEL

Effect level:

ca. 1 mg/kg bw/day

Based on:

element

Basis for effect level:

body weight and weight gain

changes in number of pregnant

clinical signs

dead fetuses

effects on pregnancy duration

food consumption and compound intake

gross pathology

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Dose descriptor:

NOAEL

Effect level:

ca. 7.09 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

changes in number of pregnant

clinical signs

dead fetuses

early or late resorptions

effects on pregnancy duration

food consumption and compound intake

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): effects observed, treatment-related
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

The viability and survival indices were unaffected.

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

no effects observed

Description (incidence and severity):

The viability and survival indices were unaffected.
Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development.

External malformations:

not specified

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

no effects observed

Description (incidence and severity):

Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Dose descriptor:

NOAEL

Effect level:

ca. 1 other: mg Fe/kg

Based on:

element

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in postnatal survival

Dose descriptor:

NOAEL

Effect level:

7.09 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in postnatal survival

Developmental effects observed:

no

F0 Generation: No deaths, and no animals were sacrificed in poor condition during the study. Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group. There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg. Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group. There were no treatment-related gross pathological changes. Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

F1 Generation: The viability and survival indices were unaffected. There were no treatment-related clinical findings. Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was administered to pregnant rats from gestation day 6 to 17 and throughout postpartum day 21 (sanofi-aventis Canada Inc., 2009). The employed doses were 1, 5 and 10 mg Fe /kg bw.

F0 Generation: No deaths, and no animals were sacrificed in poor condition during the study. Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group. There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg. Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group. There were no treatment-related gross pathological changes. Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment.

F1 Generation: The viability and survival indices were unaffected. There were no treatment-related clinical findings. Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

A NOAEL of 1.0 mg Fe/kg can be established here for maternal toxicity. This corresponds to a NOAEL of 7.09 mg/kg bw/day of the traget substance iron glucoheptonate.

Reference 6

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the source and the target substance and the expected identical behaviour in the human or animal body. This is based on the fact, that they both are metal complexes consisting of iron and sugar-like carbohydrates that are believed to share the same absorption, distribution and metabolic pathways.
The administration of sodium ferric glucoheptonate via injection represents a worst case scenario, since any absorption via the oral, dermal and inhalation route could not exceed the 100 % absorption rate applicable in the case of an injection. However, in respect to developmental toxicity the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity, 2) the same oxidation status of the iron ion in the body, 3) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 4) its identical limited elimination mechanisms.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: sodium ferric gluconate complex in sucrose injection
Each vial of 5 mL of FERRLECIT contains 12.5 mg/mL (62.5 mg/5 mL vial) of elemental iron as the sodium salt of a ferric ion gluconate complex in alkaline aqueous solution with approximately 20% sucrose w/v (195 mg/mL) in Water for Injection (pH 7.7 - 9.7). The solution contains 0.9% w/v (9 mg/mL) benzyl alcohol as preservative.
It is used to replete and maintain the total body content of iron.
The substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.

Target Chemical: Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).

Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The calculation of a hazard value for iron glucoheptonate is based on 76 % content of iron glucoheptonate in the registered product. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION
Sodium iron gluconate (source) and Sodium Iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - contain the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length. In case of sodium iron gluconate two gluconic acid-chains (C6H11O7-) are involved and in case of iron glucoheptonate it is C7H10O8.
It has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations (Life Science Research Office, 1978, cited in OECD SIDS (2004))”. Moreover, lactonisation occurs at low pH values (i.e. observed under pH 3.8 in case of Ca gluconate complexes) that would hinder complexation (Pallagi et al., 2010).
After administration, the sugar residues, which differ by one methyl rest, will both be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to gluconate or glucoheptonate moiety up to considerable amounts.
Taken together, both substances are expected to have an identical toxicodynamic and toxicological behaviour, which is based on the fact that these similar structures are metabolised by the same pathways, leading to the same substances.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality.
Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality.
Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

no effects observed

Description (incidence and severity):

Both treatment groups consumed more water than the controls, but a significant difference was not observed.

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no treatment-related gross pathological changes.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Details on results:

The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

no effects observed

Description (incidence and severity):

The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses.
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses.

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

ca. 4 other: mg Fe/kg

Based on:

element

Basis for effect level:

body weight and weight gain

changes in number of pregnant

changes in pregnancy duration

dead fetuses

food consumption and compound intake

gross pathology

mortality

water consumption and compound intake

Dose descriptor:

NOAEL

Effect level:

28.35 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

changes in number of pregnant

changes in pregnancy duration

dead fetuses

food consumption and compound intake

gross pathology

mortality

water consumption and compound intake

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

There was no difference in the litter size or birth weights between the controls and 4 mg/kg group.
There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): effects observed, treatment-related
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): There was no difference in the litter size or birth weights between the controls and 4 mg/kg group.
There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups.

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Description (incidence and severity):

There was no difference in the litter size or birth weights between the controls and 4 mg/kg group.

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

No treatment related anomalies were observed.

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

No treatment related anomalies were observed.
However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Visceral malformations:

no effects observed

Description (incidence and severity):

No treatment related anomalies were observed.

Other effects:

no effects observed

Description (incidence and severity):

No treatment related anomalies were observed.
However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Dose descriptor:

NOAEL

Effect level:

ca. 4 other: mg Fe/kg

Based on:

element

Sex:

male/female

Basis for effect level:

fetal/pup body weight changes

changes in litter size and weights

external malformations

skeletal malformations

visceral malformations

Dose descriptor:

NOAEL

Effect level:

28.35 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

fetal/pup body weight changes

changes in litter size and weights

external malformations

skeletal malformations

visceral malformations

Developmental effects observed:

no

Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality. Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake. Both treatment groups consumed more water than the controls, but a significant difference was not observed. The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Conclusions:

These results are of high relevance for the substance iron glucoheptonate, since sodium ferric gluconate complex in sucrose injection is a highly recommended read across substance, due to its similar chemical behaviour and its similar uses.

Executive summary:

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant rats from gestation day 6 to 15 (sanofi-aventis Canada Inc., 2009). The employed doses were 4 and 20 mg Fe /kg bw. Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality. Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake. Both treatment groups consumed more water than the controls, but a significant difference was not observed. The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

A NOAEL of 4.0 mg Fe/kg can be established here for maternal toxicity. This corresponds to a value of 28.35 mg/kg bw/day of the target substance iron glucoheptonate.

Reference 7

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to developmental toxicity after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Glucono-delta-lactone and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).
Purity: Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The iron glucoheptonate content in the registered product is 76 %. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their developmental toxicity, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the development of pups of rats, mice, hamsters and rabbits.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

not specified

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 594 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Basis for effect level:

other: not specified

Fetal body weight changes:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

not specified

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

not examined

Dose descriptor:

NOAEL

Effect level:

> 594 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Sex:

male/female

Basis for effect level:

other: not specified

Abnormalities:

no effects observed

Developmental effects observed:

no

Conclusions:

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Executive summary:

Glucono-delta-lactone was administered to Wistar rats for 10 days (from day 6 - 15 of gestation) at doses of 0, 5.94, 27.6, 128.0, 594.0 mg/kg bw/day. A NOAEL of > 594 mg/kg bw/day for maternal and developmental toxicity (teratogenicity) was determined.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Reference 8

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to developmental toxicity after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Glucono-delta-lactone and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).
Purity: Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The iron glucoheptonate content in the registered product is 76 %. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their developmental toxicity, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the development of pups of rats, mice, hamsters and rabbits.


4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

not specified

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 695 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Basis for effect level:

other: not specified

Fetal body weight changes:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

not specified

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

not examined

Dose descriptor:

NOAEL

Effect level:

> 695 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Sex:

male/female

Basis for effect level:

other: not specified

Developmental effects observed:

no

Conclusions:

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Executive summary:

Glucono-delta-lactone was administered to CD-1 mice for 10 days (from day 6 - 15 of gestation) at doses of 0, 6.95, 32.5, 150, 695 mg/kg.. A NOAEL of > 695 mg/kg bw for maternal and developmental toxicity (teratogenicity) was determined.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Reference 9

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to developmental toxicity after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Glucono-delta-lactone and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).
Purity: Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The iron glucoheptonate content in the registered product is 76 %. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their developmental toxicity, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the development of pups of rats, mice, hamsters and rabbits.


4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

not specified

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 560 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Basis for effect level:

other: not specified

Fetal body weight changes:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

not specified

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

not examined

Dose descriptor:

NOAEL

Effect level:

> 560 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Sex:

male/female

Basis for effect level:

other: not specified

Developmental effects observed:

no

Conclusions:

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Executive summary:

Glucono-delta-lactone was administered to hamster for 5 days (from day 6 - 10 of gestation) at doses of 0, 5.60, 26.0, 121, 560 mg/kg.. A NOAEL of > 560 mg/kg bw for maternal and developmental toxicity (teratogenicity) was determined.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Reference 10

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to developmental toxicity after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Glucono-delta-lactone and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).
Purity: Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The iron glucoheptonate content in the registered product is 76 %. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their developmental toxicity, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the development of pups of rats, mice, hamsters and rabbits.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

not specified

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 780 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Basis for effect level:

other: not specified

Fetal body weight changes:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

not specified

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

not examined

Dose descriptor:

NOAEL

Effect level:

> 780 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Sex:

male/female

Basis for effect level:

other: not specified

Abnormalities:

no effects observed

Developmental effects observed:

no

Conclusions:

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Executive summary:

Glucono-delta-lactone was administered to Dutch rabbits for 13 days (from day 6 - 18 of gestation) at doses of 0, 7.80, 36.2, 168.5, 780.0 mg/kg. A NOAEL of > 780 mg/kg bw for maternal and developmental toxicity (teratogenicity) was determined.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Reference 11

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to developmental toxicity after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Glucono-delta-lactone and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).
Purity: Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The iron glucoheptonate content in the registered product is 76 %. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than to the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their developmental toxicity, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the development of pups of rats, mice, hamsters and rabbits.

Please refer also to the extended-read-across statement attached in section 13 of this IUCLID file

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical for the endpoint oral repeated dose toxicity.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

no effects observed

Description (incidence and severity):

During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

There were no death.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

During pregnancy, no abnormalities were observed in the body weight change in any of the dose groups.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

During pregnancy, no abnormalities were observed in the food consumption in any of the dose groups.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Details on results:

During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Number of abortions:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Early or late resorptions:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Dead fetuses:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.DescriptionIncidenceAndSeverityEffectsOnPregnancyDuration): no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Other effects:

not examined

Details on maternal toxic effects:

In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Dose descriptor:

NOAEL

Effect level:

> 4 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Basis for effect level:

changes in number of pregnant

changes in pregnancy duration

clinical signs

dead fetuses

early or late resorptions

effects on pregnancy duration

food consumption and compound intake

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Changes in postnatal survival:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

External malformations:

no effects observed

Description (incidence and severity):

There was no influence of the drug on the external appearance, organs, or skeletons of the foetuses.

Skeletal malformations:

no effects observed

Description (incidence and severity):

There was no influence of the drug on the external appearance, organs, or skeletons of the foetuses.

Visceral malformations:

no effects observed

Description (incidence and severity):

There was no influence of the drug on the external appearance, organs, or skeletons of the foetuses.

Other effects:

not examined

Details on embryotoxic / teratogenic effects:

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Dose descriptor:

NOAEL

Effect level:

> 4 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Sex:

male/female

Basis for effect level:

fetal/pup body weight changes

changes in litter size and weights

changes in postnatal survival

external malformations

skeletal malformations

visceral malformations

Abnormalities:

no effects observed

Developmental effects observed:

no

During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Conclusions:

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Executive summary:

In the experiments glucono-delta-lactone was administered orally to female nulliparous rats for 10 days and the fetuses were observed by laparotomy on pregnancy day 21. Several dams in each group were allowed to deliver spontaneously, and the offspring were observed until postnatal day 21. The report does not contain specific information on the method used. During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

A NOAEL of > 4000 mg/kg bw/day was established for rats.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Reference 12

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to read-across statement attached under section 13 of this IUCLID file.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rationale for the analogue approach is the high structural similarity between the organic part of the source and the target substance and their expected identical behaviour in the human or animal body.
The target substance – as one member in the group of the chelate complexes - is known to dissociate in the upper GI tract at low pH values into the metal ion and the glucoheptonic acid anion.
The read-across substances gluconic acid, glucono-delta-lactone, sodium gluconate, potassium gluconate and calcium gluconate similarly release gluconate anions which are as well sugar-like compounds and are metabolised by the same metabolic pathways as glucoheptonate anion, and are indeed intermediate metabolites, which are partly build when the glucoheptonate anion is broken down.
In respect to developmental toxicity after oral administration the source and the target substances are expected to bear the same toxicity potential based on their 1) structural similarity and 2) the same metabolic fate of gluconic acid and glucoheptonic acid and finally 3) their identical excretion mechanisms.

Therefore, by using the toxicity profile of glucono-delta-lactone and sodium gluconate, the absence of toxicity of the organic moiety of the target molecule - glucoheptonate anion - can be confirmed.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Glucono-delta-lactone CAS 90-80-2
SMILES: C([C@@H]1[C@H]([C@@H]([C@H](C(=O)O1)O)O)O)O
MW 178.14 g/mol
The molecular formula is C6H10O6
Purity (%) of Glucono-delta-lactone: 99-101% (OECD SIDS, 2004)

Glucono-delta-lactone and sodium iron glucoheptonate complex (HGA:Fe-1:1) (target) are structurally very similar. Both - the source and the target substance - are built of the same types of hydrocarbon constituents (sugar residues), which are only variable in carbon chain length (gluconic acid-chains (C6H11O7-) and glucoheptonate C7H10O8).

Target Chemical:
Sodium Iron glucoheptonate complex (HGA:Fe-1:1), CAS 1821694-04-5,
SMILES [Na+].[H]C([H])(O)C([H])(O)C1([H])O[Fe]2OC([H])(C([O-])=O)C([H])(O2)C1([H])O,
MW 354.8 g/mol (trihydrated from) or 300.8g/mol (anhydrous form)
The molecular formula is C7FeH10NaO8 *3H2O (trihydrated form).
Purity: Information on purity of the registered substance is provided in the target record under "Test material" as confidential. The iron glucoheptonate content in the registered product is 76 %. Other components are ammonium sulfate and sodium sulfate. Ammonium sulfate and sodium sulfate are considered not to impact the reproductive toxicity of the target substance to a significant degree. No adverse effects were identified for ammonium and sulfate ions in different reproductive and developmental toxicity studies (OECD SIDS, 2004). Therefore, the iron ion is the only toxicological relevant component of the registered substance.

3. ANALOGUE APPROACH JUSTIFICATION

Gluconates and their derivatives all belong to the aldonic acids (Escandar et al., 1992; Frutos et al., 1998) because they are derivatives of aldoses, sugars that contain one aldehyde group, which is oxidised to carboxylic group (Berg et al., 2007). They form lactone form, a ring structure the same as in the sugar’s cyclic hemiacetal form (Berg et al., 2007).
The dissociation of metal gluconate and glucoheptonate complexes at low pH values in the upper GI tract has been confirmed in a lot of investigations, which show gluconate and glucoheptonate complexes to be more stable at alkaline conditions, while the complexes were not stable enough to be detected at acidic conditions (Escandar et al., 1996; Sawyer, 1964; Gyurcsik and Nagy, 2000; Alekseev et al., 1998). Consequently, the metal ion and the gluconic or glucoheptonic acid anion will be subject to a more or less independent fate of absorption into the systemic circulation – independent from the organic moiety and will underlie normal physiological pathways responsible for metal uptake.
Considering this dissociation, the information that it has generally been shown by a substantial body of evidence, that the toxicity profiles of chelate compounds in general depend mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body is a very useful information. In the OECD SIDS report is mentioned “Evidence from the reviewed literature suggests that the eventual toxicity of the gluconate salts would be attributable to the cation rather than of the gluconate moiety of these substances. Acute toxicity responses to the various gluconate salts are comparable with other salts of the same metals and long-term toxicities seem related to the tissue deposition of these metals. Because toxicological effects of these gluconates appear to be related to their cationic components, safe and acceptable levels in foods are limited only by the nature of the specific cations…(Life Science Research Office, 1978, cited in OECD SIDS (2004))”.
The released free gluconate or glucoheptonate anions, however, can in the posterior parts of the GI tract – in the small intestines, where pH raises - further sequester luminal or mucosal metal affecting the absorption. The impact of the released free gluconate or glucoheptonate anions on absorption of metals has been addressed by a lot of investigations, which showed that gluconate complexes actually enhanced absorption of metals increasing their bioavailability. Absorption of the nutrient metals was higher from gluconates than from the soluble inorganic compounds (i.e. Cousins, 1985, please refer to the detailed read-across statement attached in IUCLID section 13). Absorption of nutrient metals from glucoheptonate complexes seems to be equal to that from gluconate complexes (i.e. Durisova et al., 1985, please refer to the detailed read-across statement attached in IUCLID section 13).

After absorption, the above mentioned sugar residues, will all be metabolised by the pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) for the synthesis of the same 5-carbon sugars. In fact, no toxicity is attributed to the gluconate or glucoheptonate moiety up to considerable amounts.

In conclusion, gluconate and glucoheptonate anions form complexes with metals of the same geometry and stoichiometry. The same functional groups of the ligand are involved in the formation of coordinative bonds. Identical behaviour of gluconates and glucoheptonates depending on pH, molar concentration of metal: ligand components and physical state is verified by analytical methods. Based on the structural similarity of gluconates and glucoheptonates, their functional groups, composition, toxicodynamic, toxicokinetic, and toxicological behaviour, one can expect a very similar behaviour of these substances in living organisms.
Concerning their developmental toxicity, the available data from oral repeated dose toxicity studies on sodium gluconate and a teratogenicity study on glucono-delta-lactone show both substances not to have an impact on the development of pups of rats, mice, hamsters and rabbits.

4. DATA MATRIX
The table attached in section 13 shows the available data relevant to justify the read-across from the source to the target chemical.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

no effects observed

Description (incidence and severity):

During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

There were no death.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

During pregnancy, no abnormalities were observed in the body weight change in any of the dose groups.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

During pregnancy, no abnormalities were observed in the food consumption in any of the dose groups.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Details on results:

During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Number of abortions:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Early or late resorptions:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Dead fetuses:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.DescriptionIncidenceAndSeverityEffectsOnPregnancyDuration): no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring.

Other effects:

not examined

Details on maternal toxic effects:

In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Dose descriptor:

NOAEL

Effect level:

> 4 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Basis for effect level:

body weight and weight gain

clinical signs

dead fetuses

food consumption and compound intake

mortality

pre and post implantation loss

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Changes in postnatal survival:

no effects observed

Description (incidence and severity):

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

External malformations:

no effects observed

Description (incidence and severity):

There was no influence of the drug on the external appearance, organs, or skeletons of the foetuses.

Skeletal malformations:

no effects observed

Description (incidence and severity):

There was no influence of the drug on the external appearance, organs, or skeletons of the foetuses.

Visceral malformations:

no effects observed

Description (incidence and severity):

There was no influence of the drug on the external appearance, organs, or skeletons of the foetuses.

Other effects:

not examined

Details on embryotoxic / teratogenic effects:

Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Dose descriptor:

NOAEL

Effect level:

> 4 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Glucono-Delta-Lactone

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in litter size and weights

changes in postnatal survival

external malformations

skeletal malformations

visceral malformations

Abnormalities:

no effects observed

Developmental effects observed:

no

During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

Conclusions:

In summary, these negative data on the teratogenicity of glucono-delta-lactone, together with the natural occurrence of gluconic acid in the human metabolism sufficiently support the lack of developmental toxicity for all the gluconates of the category.
These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Executive summary:

In the experiments glucono-delta-lactone was administered orally to female nulliparous mice for 10 days and the fetuses were observed by laparotomy on pregnancy day 18. Several dams in each group were allowed to deliver spontaneously, and the offspring were observed until postnatal day 21. The report does not contain specific information on the method used. During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

A NOAEL of > 4000 mg/kg bw/day was established for mice.

These results are also relevant for iron glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, the fact that glucono-delta-lactone does not provoque any effects on the reproductive system or on the developing fetus is important.

Reference 13

Endpoint:

developmental toxicity

Type of information:

other: Acceptable well documented data originating from peer-reviewed source.

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

secondary literature

Guideline:

other:

Version / remarks:

not specified

Principles of method if other than guideline:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

not specified

Species:

other: mouse and rat

Strain:

not specified

Details on test animals or test system and environmental conditions:

not specified

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on exposure:

no details given

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

no details given

Details on mating procedure:

no details given

Duration of treatment / exposure:

not specified

Frequency of treatment:

not specified

Duration of test:

not specified

Remarks:

not specified

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

no details given

Maternal examinations:

reduced body weight, increased implantation loss

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

reduced body weight

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

reduced body weight

Pre- and post-implantation loss:

effects observed, treatment-related

Description (incidence and severity):

increased implantation loss

Dose descriptor:

dose level: reduced body weight in dams, increased implantation loss

Effect level:

1 200 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: reduced body weight in dams, increased implantation loss

Dose descriptor:

NOAEL

Effect level:

380 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: not specified

Dose descriptor:

NOAEL

Effect level:

380 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: not specified

Developmental effects observed:

no

Conclusions:

The relevant maternal and developmental toxicity NOAELs were 380 mg/kg bw/day iron sulfate in both rats and mice (reduced body weight in dams, increased implantation loss at 1200 mg/kg bw/day).

Executive summary:

The relevant maternal and developmental toxicity NOAELs were 380 mg/kg bw/day iron sulfate in both rats and mice (reduced body weight in dams, increased implantation loss at 1200 mg/kg bw/day).

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

996.56 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The quality of the whole database is considered sufficient for estimation of reproductive toxicity potential, because of the multipicity of available data for the different read-across substances.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Data on sodium ferric gluconate complex in sucrose injection

Ferrlecit (sodium ferric gluconate in sucrose injection) was adminstered to pregnant rats from gestation day 6 to 17. The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw/day. Two animals in the 15 mg/kg group and one animal in the 30 mg/kg group died or were sacrificed in poor condition during the study. Clinical findings prior to sacrifice or death included vaginal discharge, pallor, fur staining, cold to touch, hunched posture, dehydration, weakness, lying on side, and/or decreased respiratory rate/labored breathing, and one dam had started to litter. Necropsy findings for the respective animals included dark discoloration of the ingesta, multiple dark areas on the stomach, pale or irregular area/foci on the livers, enlarged spleen, dark area/small thymus and dark fluid in the uterus or bladder. Common findings for the animals in the 15 and 30 mg/kg groups included yellow/orange/red urine staining of the urogenital region. Local effects included blue discoloration of the tail seen primarily in the 5 mg/kg group and above. Dose-related body weight decreases were evident between Days 6 and 9 of gestation, with body weights for the 30 mg/kg group were remained lower through gestation Day 18. Food consumption from Days 6 to 9 of gestation showed dose-related reductions. Food consumption was decreased in the 15 and 30 mg/kg/day groups between Days 15 to 18 and Days 9 to 18 of gestation, respectively. Necropsy of the animals examined at cesarean section revealed clear fluid in the abdomen, discolored / enlarged or dark lymph nodes, multiple pale areas on the liver, swollen or discolored pancreas, enlarged spleen. Dark areas on the uterus were seen among the dams in the 15 and/or 30 mg/kg groups. The pregnancy rate was at least 83% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, the sex ratio, and the pre and postimplantation losses were unaffected by treatment. Fetal weights were slightly reduced in the 15 and 30 mg/kg groups. There were no major malformations or minor anomalies observed externally.

Moreover, Ferrlecit was adminstered to pregnant rats from gestation day 6 to 17 and throughout postpartum day 21. The employed doses were 1, 5 and 10 mg Fe /kg bw/day. In the F0 Generation, no deaths were observed, and no animals were sacrificed in poor condition during the study. Local clinical effects at the injection site, including blue discoloration of the tail, were seen at a higher incidence in the 5 and 10 mg/kg groups. Dark discoloration of the urine was seen in the 10 mg/kg group. There were significant dose-related weight losses for the 5 and 10 mg/kg groups from Days 6 to 9 of gestation. There was an increased weight gain at the 10 mg/kg level for Days 9 to 12 of gestation, and between Days 12 and 15 of gestation there was again a lower weight gain. During lactation there was marked variability of weight gains with lower values being seen in the period Days 0 to 4 post partum for the 5 and 10 mg/kg groups and smaller weight losses between Days 17 and 21 post partum at 10 mg/kg. Food intakes from Days 6 to 9 and Days 15 to 18 of gestation showed dose-related reductions which were significant (P<0.05) in the 10 mg/kg group. There were no treatment-related gross pathological changes. Maternal performance in terms of the length of gestation, duration of parturition, and number of live, dead and malformed pups at birth was unaffected by treatment. In the F1 Generation, the viability and survival indices were unaffected. There were no treatment-related clinical findings. Pup weights (male, female, and total) were slightly lower at birth in the 10 mg/kg group. These differences were significantly lower on Day 4 post partum and continued to be significant until Day 21 post partum. Slightly lower pup weights were seen on Day 7 post partum, with significantly lower values on Days 14 and 21 post partum in the 5 mg/kg group. Evaluation of the data from the F1 adult animals indicated that there were no adverse clinical observations. Behavioral and maturational assessments indicated that there were no direct effects of drug treatment on normal development. At the highest dose, there was an increase in the mean time to vaginal opening and an increase in exploration activity counts on Day 35 postpartum (but not on Day 60). Both of these findings are attributed to the decrease in the rate of maternal weight gains. The reproductive capacity of the F1 generation was not affected and their offspring were normal with respect to clinical observations and weight gains.

In addition, Ferrlecit was adminstered to pregnant rats from gestation day 6 to 15. The employed doses were 4 and 20 mg Fe /kg bw/day. Treatment of pregnant rats at a dose of 20 mg/kg resulted in marked effects that included lower maternal weight gain, lower food consumption, reduced gestation index, a significantly lower litter size, increased resorption sites, and fetal mortality. Treatment at 4 mg/kg did not show any difference from controls regarding weight gain or food intake. Both treatment groups consumed more water than the controls, but a significant difference was not observed. The fertility index was identical between all groups. There was no difference between the control and the 4 mg/kg group regarding the gestation index or the number of dead fetuses. There was no difference in the litter size or birth weights between the controls and 4 mg/kg group. There was a significant difference in the birth weights of both the males and females in the 20 mg/kg group compared to the control and 4 mg/kg groups. No treatment related anomalies were observed. However, many of the 20 mg/kg fetuses showed a retardation in ossification of the cranial bones. This was interpreted to indicate a delay in general development associated with reduced maternal weight gains and food consumption. There was no evidence of teratogenicity at any dose level.

Additionally, Ferrlecit was adminstered to pregnant mice from gestation day 6 to 15. The employed doses were 2.5, 5, 15 and 30 mg Fe /kg bw/day. No treatment-related deaths were observed. Local effects at the treatment site included swelling and blue discoloration of the tail. Skin lesions and or areas of scab formation were seen on the tail in all groups, including the control. Body weights and food consumption for the treated groups were comparable to the controls. No gross pathological findings were recorded. The pregnancy rate was 100% in all groups. The number of corpora lutea, implantation sites, live fetuses, dead fetuses, resorptions, the sex ratio, and the pre- and postimplantation losses were unaffected by treatment. Fetal weights were similar to control values. The incidence of major malformations and minor anomalies was unaffected.

Moreover, Ferrlecit was adminstered to pregnant mice from gestation day 6 to 15. The employed doses were 10, 30 ans 100 mg Fe /kg bw/day. No drug related mortality was observed. Effects seen at the injection sites in the 30 and 100 mg/kg groups included dry skin and ulceration on the tail, and black discoloration at the tip of the tail. Decreased activity and red vaginal discharge were also observed for some mice in the 100 mg/kg group. The body weight gains were decreased for the intervals Days 6 to 9 and Days 15 to 18 for the 100 mg/kg group. Body weights by Day 18 of gestation were significantly decreased compared with controls. Food consumption for the 100 mg/kg group was significantly decreased between Days 6 and 9 of gestation. Gross pathological findings in the 30 and 100 mg/kg groups included splenic enlargement and focal to multi-focal hepatic pallor. Other hepatic alterations including prominent lobular architecture and/or irregular pattern were also seen for a few 100 mg/kg group mice. Subcutaneous edema, sometimes with ascites and/or edema affecting the pancreas and cecum, was seen in three 100 mg/kg mice. The number of early resorptions was slightly increased in the 100 mg/kg group. Evaluation of the number of resorptions per litter and numbers of litters with total resorption were indicative of embryolethality. The numbers of corpora lutea, implantation sites, dead fetuses, the sex ratio and the pre-implantation losses in the control and treated groups were similar. Fetal weights were significantly (P< 0.01) reduced in the 100 mg/kg group. There were no drug induced malformations seen in this study. The overall incidence of fetuses with minor skeletal anomalies was significantly increased in the 30 and 100 mg/kg groups. This resulted primarily from increased incidences of reduced numbers of ossified caudal vertebrae and a higher incidence of reduced numbers of ossified phalanges in the fore and/or hind paws. The percentage of fetuses with sternebral variants was increased in the 30 and 100 mg/kg groups. These latter findings were probably associated with the reduced growth of the offspring which was a consequence of reduced weight gains in the maternal animals at the high dose.

In conclusion, FERRLECIT (sodium ferric gluconate complex in sucrose injection) was not teratogenic at doses of elemental iron up to 100 mg/kg bw/day (300 mg/m²/day) in mice and 20 mg/kg bw/day (120 mg/m²/day) in rats. On a body surface area basis, these doses were 1.3 and 3.24 times the recommended human dose (125 mg/day or 92.5 mg/m²/day) for a person of 50 kg body weight, average height and body surface area of 1.46 m².

Finally, Ferrlecit was adminstered to pregnant rabbits from gestation day 1 to 23 and 28. The employed dose was 1.875 mg Fe /kg bw/day. 1.875 mg/kg bw/day did not result in changes in the number and weight of the fetuses, in the number of live births, or in the structures of the main organs of the fetuses. There was no teratogenic effect on the morphology of the skeleton, limbs, or viscera. The fetuses were similar in number and weight to those from the animals treated with vehicle.

In conclusion, FERRLECIT (sodium ferric gluconate complex in sucrose injection) was not teratogenic at doses of elemental iron of 1.875 mg/kg/day in rabbits.

Data on gluconates and derivatives (SIDS, 2004)

 

Glucono-delta-lactone was administered to Wistar rats for 10 days (from day 6 - 15 of gestation) at doses of 0, 5.94, 27.6, 128.0, 594.0 mg/kg bw/day. A NOAEL of > 594 mg/kg bw/day for maternal and developmental toxicity (teratogenicity) was determined.

Glucono-delta-lactone was administered to CD-1 mice for 10 days (from day 6 - 15 of gestation) at doses of 0, 6.95, 32.5, 150, 695 mg/kg bw/day. A NOAEL of > 695 mg/kg bw/day for maternal and developmental toxicity (teratogenicity) was determined.

Glucono-delta-lactone was administered to hamster for 5 days (from day 6 - 10 of gestation) at doses of 0, 5.60, 26.0, 121, 560 mg/kg bw/day. A NOAEL of > 560 mg/kg bw/day for maternal and developmental toxicity (teratogenicity) was determined.

Glucono-delta-lactone was administered to Dutch rabbits for 13 days (from day 6 - 18 of gestation) at doses of 0, 7.80, 36.2, 168.5, 780.0 mg/kg bw/day. A NOAEL of > 780 mg/kg bw/day for maternal and developmental toxicity (teratogenicity) was determined.

 

Moreover, further experiments with glucono-delta-lactone in rats and mice are available.

Glucono-delta-lactone was administered orally to female nulliparous rats or mice for 10 days and the fetuses were observed by laparotomy on pregnancy day 21 or 18, respectively. Several dams in each group were allowed to deliver spontaneously, and the offspring were observed until postnatal day 21. The report does not contain specific information on the method used. During pregnancy, no abnormalities were observed in the general condition, body weight change or food consumption in any of the dose groups, nor were any death. In observation of dams after laparotomy, no abnormalities were detected in the number of implantations, dead foetuses, live offspring or mean body weight of offspring, nor was there any influence of the drug on the external appearance, organs, or skeletons of the foetuses. Observation of the dams allowed to deliver spontaneously, protraction of the duration of pregnancy or abnormalities at birth were not observed, nor any influence of the drug detected in the mortality rate, body weight gain, behavior, external appearance or visceral abnormalities of the offspring during the period of nursing.

A NOAEL of > 4000 mg/kg bw/day was established for rats and mice.

Justification for classification or non-classification

Effects on reproductive performance/fertility and developmental toxicity were assessed by means of a read-across approach. The read-across substances sodium ferric gluconate complex in sucrose injection and gluconates and derivatives caused no reproductive toxicity and no teratogenicity in the rat/mice/hamster/rabbit/dog in the available toxicity studies. The NOAEL of iron glucoheptonate after oral application was calculated from the source substances ferric chloride and iron sulfate. The NOAELs were 1204.95 mg/kg bw/day for reproductive toxicity and 996.56 mg/kg bw/day for developmental toxicity.

Accordingly, iron glucoheptonate is not subject to classification for toxicity to reproduction and developmental effects according to European Regulation (EC) No 1272/2008.