Reaction products of sodium glucoheptonate with zinc sulfate and sodium hydroxide

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

To address the endpoint toxicity to reproduction, read-across on gluconates and derivatives and zinc 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 zinc salts

The influence of zinc feeding on conception of rats was studied using anhydrous ZnSO4 (Pal and Pal, 1987). Two tests were conducted involving the dosing of female, virgin rats with zinc either after coitus or 21 to 26 days prior to mating. The dosage was continued during the pregnancy until the female rats were sacrificed on day 18 of gestation. Weight of the placenta was not significantly different between the experimental group and their respective control group. Regarding the test without ZnSO4 gavage prior to mating, 12 out of 15 animals of the control group and the treated group were mated, of which 12 and 5 females, respectively, conceived during the study. In the test with ZnSO4 gavage prior to mating, 11 out of 18 animals of the control group and 15 out of 18 animals of the treated group were mated, of which 10 and 14 females, respectively, conceived during the study. When zinc was first added to the food after coitus, the "implanation sites per pregnant female was lower in the zinc treated group (5.0) than in the control rats (7.0) however the difference was not significant (t-test). Implantation sites per mated female were 7.0 in the control group and 2.1 in the zinc fed experimental group." When zinc treatment started 21 to 26 days prior to mating there was no significant difference in incidents of conception between the treated group and the control group. Also, there was no significant difference between the two groups regarding implantation sites expressed per mated or pregnant female. Also, the mean fetal and placental weights were similar. No stillbirth or malformation of the fetuses for either of the tests was detected. For the female parent, the dose of 4,000 ppm zinc showed either no effects (in case of dosage start prior to mating) or a slight effect on reproduction performance (in case of dosage started after coitus). For the F1 generation (examination of fetuses) no effect of the dosage of the female parent animal was observed. Converted to the target substance zinc glucoheptonate, this corresponds to a NOAEL of 25247.71 ppm or 1262.39 mg/kg bw/day.

The effect of zinc on reproduction toxicity was studied by Uriu-Hare et al. (1989). Starting on day 0 of gestation, rats were fed a low-Zn diet (4.5 mg/kg diet, 1.42 mg ZnGHA/kg bw/day), an adequate-Zn diet (24.5 mg/kg diet, 7.732 mg ZnGHA/kg bw/day), or a high-Zn diet (500 mg/kg diet, 157.8 mg ZnGHA/kg bw/day) throughout gestation. Fetuses were taken by cesarean section on gestation day 20. Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal weight gain in the diabetic groups. "Increasing dietary Zn tended to lower the resorption frequency. No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups.

In the study by Lastra et al. (1997) mice received zinc acetate in drinking water at concentrations of 500 and 1000 mg/I during the periods of gestation, lactation and post-weaning. The sequence employed in this study was: (I) 0/0 (II) 500/500 (III) 1000/1000 (IV) 0/0/0 (V) 500/500/500 and (VI) 1000/1000/1000 with their respective controls. Each group consists of 30 animals. No changes were observed in the general appearance, growth curves, hematocrit or signs of achromotrichia between treated and control animals. Group II and III showed a significant increase in 3H-thymidine-determined splenic lymphoproliferation, while groups V and VI exhibited an important decrease. A significant increase in plaque - forming cell response (IgM) was observed after the period of lactation in groups II and III as well as in groups V and VI. Zinc concentrations determined by atomic absorption in liver and thymus were significantly higher in all treated mice 42 days after birth. The applied doses of 500 and 1000 mg Zn/L correspond to doses of 179.89 mg ZnGHA/kg bw/day and 359.78 mg ZnGHA/bw/day. Results suggest that for carefully monitored periods and doses, oral zinc supplements might have a beneficial effect over some immune responses in the perinatal stages.

Data on gluconates and derivatives (SIDS, 2004)

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 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.

A 28-day oral feeding study 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.

 

These results are also relevant for zinc 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 ishows that no reproductive toxicity can be attributed to the glucoheptonate moiety of zinc glucoheptonate.

Conclusion

Based on the given information the NOAEL of 1262.39 mg/kg bw/day, which is derived from data on ZnSO4 (Pal and Pal, 1987) is regarded as suitable hazard value for the assessment of the reproductive toxicity of the registered substance.

Link to relevant study records

Reference

Reference 1

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Mice received zinc acetate in drinking water at concentrations of 500 and 1000 mg/I during the periods of gestation, lactation and postweaning. The general appearance, growth curves and hematocrit were examined in treated animals.

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

supplier: Mallinckrodt, cat. no. 8740

Species:

mouse

Strain:

Balb/c

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Laboratory of Immunology at the School of Chemistry of the Natioal University of Mexico
- Age at study initiation: (P) 6 wks
- Weight at study initiation: (P) Females: approximately 22 g;
- Fasting period before study: not specified
- Housing: Plastic cages equipped with steel covers and sterile sawdust on the floor were used.
- Diet: ad libitum (Blue-Bonnet, 2000 Biomex)
- Water (e.g. ad libitum): not specified
- Acclimation period: not specified

Route of administration:

oral: drinking water

Vehicle:

water

Details on mating procedure:

After mating, the males were separated from the females. The pregnant females were housed individually.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

One group of female, pregnant mice were exposed to Zn Acetate during gestation and lactancy. Another group of female, pregnant mice were exposed to Zn Acetate during gestation, lactancy and post-weaning.

Frequency of treatment:

daily with drinking water

Dose / conc.:

500 ppm

Remarks:

Zinc

Dose / conc.:

1 000 ppm

Remarks:

Zinc

No. of animals per sex per dose:

30 animals per group

Control animals:

yes

Litter observations:

STANDARDISATION OF LITTERS
- Litter: 6 to 8 pups/litter; amount of pups adjusted to 6 per litter.

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring: number of pups, stillbirths, live births, presence of gross anomalies, physical abnormalities, growth curves.

Statistics:

ANOVA with p value < 0.05 was considered significant.

Reproductive indices:

6 to 8 pups/litter

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

"The hematocrit values were slightly reduced in the groups that received 1000 mg/l both after 21 and 42 days."

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

"The concentration of Zn remained constant over the first 21 days,increasing significantly during the post-weaning period. An increasing tendency was observed in the treated mice at 42 days of age, the period in which thymic involution is observed in the controls."

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

effects observed, non-treatment-related

Description (incidence and severity):

"A similar reproductive index was observed between the treated animals and the control group."
"The excess of zinc did not seem to alter the viability, the offspring number, or neonatal mortality."

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

500 mg/L drinking water

Based on:

element

Sex:

female

Basis for effect level:

haematology

clinical biochemistry

reproductive performance

other: immunological findings

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

1 000 mg/L drinking water

Based on:

element

Sex:

female

Basis for effect level:

haematology

clinical biochemistry

reproductive performance

other: immunological findings

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

28.57 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

haematology

clinical biochemistry

reproductive performance

other: immunological findings

Remarks on result:

other: converted to mg/kg bw/day (please refer to 'Any other information on results incl. tables'

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

57 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

haematology

clinical biochemistry

reproductive performance

other: immunological findings

Remarks on result:

other: converted to mg/kg bw/day (please refer to 'Any other information on results incl. tables'

Remarks on result:

not measured/tested

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Description (incidence and severity):

"The excess of zinc did not seem to alter the viability, the offspring number, or neonatal mortality."

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

no effects observed

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

effects observed, treatment-related

Description (incidence and severity):

"Indirect plaque forming cells (IgG) did not show any significant response to Zn treatment."
"A significant increase in lymphocytes proliferation from mice treated with doses of 500 mg/l and 1000 mg/l with respect to control mice at the end of lactancy (21 days) (p<0.05).A significant reduction in the proliferation was also observed in mice 42 days old, treated with 500 and 1000 mg/l doses."

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

500 mg/L drinking water

Based on:

element

Sex:

male/female

Basis for effect level:

viability

mortality

developmental immunotoxicity

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

1 000 mg/L drinking water

Based on:

element

Sex:

male/female

Basis for effect level:

viability

mortality

developmental immunotoxicity

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

28.57 mg/kg bw/day

Based on:

element

Sex:

male/female

Basis for effect level:

viability

mortality

developmental immunotoxicity

Remarks on result:

other: converted to mg/kg bw/day (please refer to 'Any other information on results incl. tables')

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

57 mg/kg bw/day

Based on:

element

Sex:

male/female

Basis for effect level:

viability

mortality

developmental immunotoxicity

Remarks on result:

other: converted to mg/kg bw/day (Please refer to 'Any other information on results incl. tables')

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Dose calculation

500 mg/L Zn in drinking water/day = 0.5 g Zn/g water

default values for dose calculation for female rats (according to Golde et al., 1984 and Paulussen et al., 1998, cited in ECHA Guidance R.8)

water consumption per day (female rat) = 20 mL

body weight (female rat) = 0.35 kg

Zn intake per rat per day

0.5 mg Zn/g water/day x 20 g = 10 mg Zn/day

Zn intake per body weight/day

(10 mg Zn/day) / 0.35 kg = 28.57 mg/kg bw/day

conversion factor = 0.057

Conclusions:

No changes were observed in the general appearance, growth curves, hematocrit or signs of achromotrichia between treated and control animals. Group II and III showed a significant increase in 3H-thymidine-determined splenic lymphoproliferation, while groups V and VI exhibited an important decrease. A significant increase in plaque - forming cell response (IgM) was observed after the period of lactation in groups II and III as well as in groups V and VI. Zinc concentrations determined by atomic absorption in liver and thymus were significantly higher in all treated mice 42 days after birth. Results suggest that for carefully monitored periods and doses, oral zinc supplements might have a beneficial effect over some immune responses in the perinatal stages.

Executive summary:

In this study mice received zinc acetate in drinking water at concentrations of 500 and 1000 mg/I during the periods of gestation, lactation and post-weaning. The sequence employed in this study was (gestation/lactation/post-weaning): (I) 0/0 (II) 500/500 (III) 1000/1000 (IV) 0/0/0 (V) 500/500/500 and (VI) 1000/1000/1000 with their respective controls. Each group consists of 30 animals. No changes were observed in the general appearance, growth curves, hematocrit or signs of achromotrichia between treated and control animals. Group II and III showed a significant increase in 3H-thymidine-determined splenic lymphoproliferation, while groups V and VI exhibited an important decrease. A significant increase in plaque - forming cell response (IgM) was observed after the period of lactation in groups II and III as well as in groups V and VI. Zinc concentrations determined by atomic absorption in liver and thymus were significantly higher in all treated mice 42 days after birth. Results suggest that for carefully monitored periods and doses, oral zinc supplements might have a beneficial effect over some immune responses in the perinatal stages.

Reference 2

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:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Qualifier:

no guideline followed

Principles of method if other than guideline:

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.
The repeat 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 in water at a volume of 1 mL/ 100g bw.
A 28-day oral feeding study was conducted rats with sodium gluconate at doses of 0, 1000, 2000 and 4100 mg/kg bw.
Repeated toxicity studies in Beagle dogs were conducted with sodium gluconate administered orally for 4 weeks at 500, 1000, 2000 mg/kg bw doses.

GLP compliance:

no

Limit test:

no

Species:

other: dog

Strain:

other: Beagle

Sex:

not specified

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on mating procedure:

not applicable

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

not specified

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

500 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Dose / conc.:

2 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

12/sex/group

Control animals:

yes

Details on study design:

- Dose selection rationale: not specified
- Rationale for animal assignment (if not random): not specified
- Rationale for selecting satellite groups: not applicable
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale (if not random): not specified

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Not specified

BODY WEIGHT: Not specified

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Not specified

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Not specified

CLINICAL CHEMISTRY: Not specified.

URINALYSIS: Not specified

NEUROBEHAVIOURAL EXAMINATION: Not specified
IMMUNOLOGY: Not specified

Oestrous cyclicity (parental animals):

not specified

Sperm parameters (parental animals):

not specified

Litter observations:

not applicable as no offsprings were generated

Postmortem examinations (parental animals):

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Postmortem examinations (offspring):

not applicable as no offsprings were generated

Statistics:

no data

Reproductive indices:

not examined

Offspring viability indices:

not examined

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.

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:

not examined

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.

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.

Reference 3

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Starting on day 0 of gestation, streptozocin-induced diabetic and nondiabetic control rats were fed a low-Zn diet (4.5 µg/g diet), an adequate-Zn diet (24.5 µg/g diet), or a high-Zn diet (500 µg/g diet) throughout gestation. Fetuses were taken by cesarean section on gestation day 20 and examined.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen, Gilroy, CA
- Females: virgins
- Weight at study initiation: (P1) Females: 220-240 g
- Housing: housed individually in suspended stainless steel cages
- Diet: ad libitum
- Water: ad libitum (deionised water)
- Acclimation period: adaption to diet and light-dark cycle for 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-23 °C
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on mating procedure:

- M/F ratio per cage: not specified
- Length of cohabitation: not specified
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentrations of Zn, Cu, Mn, Fe, Mg and Ca were confirmed by flame atomic acsorption spectroscopy (AAS IL-551, Instrumentation Laboratories, Wilmington, MA).

Duration of treatment / exposure:

After mating, the rats were assigned to one of the following diets ad libitum for 20 days:
1) low Zn diet containing 4.5 µg/g diet
2) adequate Zn diet containing 24.5 µg/g diet
3) high Zn diet containing 500 µg/g diet.

Frequency of treatment:

daily with food

Dose / conc.:

4.5 other: µg/g diet

Remarks:

further referred to as "low-Zn diet"

Dose / conc.:

24.5 other: µg/g diet

Remarks:

further referred to as " adequate-Zn diet"

Dose / conc.:

500 other: µg/g diet

Remarks:

further referred to as "high-Zn diet"

No. of animals per sex per dose:

not mentioned in publication

Control animals:

no

Details on study design:

This study was designed to assess the effect of maternal Zn intake in diabetes-induced rats. For this WoE, only the results of the diabetes' control group is of interest. Consequently, the results of the diabetes group will be not discussed herein.

Parental animals: Observations and examinations:

BODY WEIGHT: Yes
- Time schedule for examinations: daily

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined on a daily basis

Postmortem examinations (parental animals):

SACRIFICE
- Maternal animals: All animals were sacrificed

EXAMINATION OF...
- number of live, dead, and resorbed fetuses
- maternal livers and kidneys
- maternal plasma and tissue analyzed for Zn, Cu, Mn, Fe, Ca, and Mg concentrations by flame AAS

Statistics:

Data were analyzed with two-way analysis of variance. The significance of observed differences among the groups was evaluated with Duncan's multiple-range test. Values of P < 0.05 were considered statistically significant

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

"Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal weight gain in the diabetic groups."

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups,

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Increasing dietary Zn tended to lower the resorption frequency.

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

4.5 mg/kg diet

Based on:

element

Sex:

female

Basis for effect level:

other: resorption frequency

Remarks on result:

other: "low-Zn diet"

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

24.5 mg/kg diet

Based on:

element

Sex:

female

Basis for effect level:

other: resorption frequency

Remarks on result:

other: "adequate-Zn diet"

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

500 mg/kg diet

Based on:

element

Sex:

female

Basis for effect level:

other: resorption frequency

Remarks on result:

other: "high-Zn diet

Critical effects observed:

no

Remarks on result:

not measured/tested

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Fetuses from dams fed the low-Zn diet had low liver Zn levels compared with those fed the adequate- and high-Zn diets."

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

effects observed, treatment-related

Description (incidence and severity):

"Maternal dietary Zn had an affect on fetal outcome. Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet. Fetuses receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses fed the low-Zn diet. No further improvement in calcification with the high-Zn diet was observed. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in group fed the high-Zn diet. Dietary Zn had only a modest effect on fetal malformation frequency, there was no further improvement in the frequency of fetal abnormalities when the high-Zn diet was fed."

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

4.5 mg/kg diet

Based on:

element

Sex:

male/female

Basis for effect level:

other: body length, Ossification of fetal vertebrae, fetal malformation frequency

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

24.5 mg/kg diet

Based on:

element

Sex:

male/female

Basis for effect level:

other: body length, Ossification of fetal vertebrae, fetal malformation frequency

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Generation:

F1

Effect level:

500 mg/kg diet

Based on:

element

Sex:

male/female

Basis for effect level:

other: body length, Ossification of fetal vertebrae, fetal malformation frequency

Critical effects observed:

no

Remarks on result:

not measured/tested

Reproductive effects observed:

no

Conclusions:

Maternal animal:
"Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal
weight gain in the diabetic groups."Increasing dietary Zn tended to lower the resorption frequency. No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups,

Fetuses:
„Fetuses from dams fed the low-Zn diet had low liver Zn levels compared with those fed the adequate- and high-Zn diets. Maternal dietary Zn had an affect on fetal outcome. Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet. Fetuses receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses fed the low-Zn diet. No further improvement in calcification with the high-Zn diet was observed. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in group fed the high-Zn diet. Dietary Zn had only a modest effect on fetal malformation frequency, there was no further improvement in the frequency of fetal abnormalities when the high-Zn diet was fed."

Executive summary:

Starting on day 0 of gestation, rats were fed a low-Zn diet (4.5 mg/kg diet), an adequate-Zn diet (24.5 mg/kg diet), or a high-Zn diet (500 mg/kg diet) throughout gestation. Fetuses were taken by cesarean section on gestation day 20. Maternal dietary Zn had a minor effect on fetal malformation frequency. The adequate- and high-Zn diets improved fetal length and weight.

Maternal animal:

"Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal weight gain in the diabetic groups."Increasing dietary Zn tended to lower the resorption frequency. No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups.

 

Fetuses:

„Fetuses from dams fed the low-Zn diet had low liver Zn levels compared with those fed the adequate- and high-Zn diets. Maternal dietary Zn had an affect on fetal outcome. Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet. Fetuses receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses fed the low-Zn diet. No further improvement in calcification with the high-Zn diet was observed. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in group fed the high-Zn diet. Dietary Zn had only a modest effect on fetal malformation frequency, there was no further improvement in the frequency of fetal abnormalities when the high-Zn diet was fed."

Reference 4

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1987

Reliability:

2 (reliable with restrictions)

Principles of method if other than guideline:

- Principle of test: Within one test, zinc supplement was added to the food from day on which female rat was pregnant.
Another test was conducted whereby the female rats were fed with the supplement of ZnSO4 for 21 days prior to mating. The feeding with zinc continued during the mating phase of a maximum of 5 days. Other procedures like the ongoing feeding with ZnSO4 during pregnancy were the same for both tests.
- Short description of test conditions: The experimental groups consisted of 12 and 15 rats for the two tests, respectively. Zinc was added as ZnSO4 in the feed of the experimental group at 4,000 ppm.
- Parameters analysed / observed: Estrus cycle regularly studied by vaginal smear technique, Fetuses were counted postmortem and examined for stillbirth and malformation, Fetuses were weighted together.

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

ZnSO4 anhydrous

Species:

rat

Strain:

other: Charles-Foster

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Females: virgin rats with a regular estrus cycle
- Housing: each female housed in cage
- Diet: ad libitum (crushed rat feed of Hindutan Lever (India))
- Water: ad libitum

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: zinc was added as ZnSO4 in the feed of the experimental group at 4,000 ppm.

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: maximum period of 5 days
- Proof of pregnancy: sperm in vaginal smear referred to as day 1 of pregnancy
- After successful mating each pregnant female was caged separately.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Within one test, zinc supplement was added to the food from day on which female rat was pregnant.
Another test was conducted whereby the female rats were fed with the supplement of ZnSO4 for 21 days prior to mating. The feeding with zinc continued during the mating phase of a maximum of 5 days. Other procedures like the ongoing feeding with ZnSO4 during pregnancy were the same for both tests.

Frequency of treatment:

daily with food

Dose / conc.:

4 000 ppm

No. of animals per sex per dose:

The experimental groups consisted of 12 and 15 rats for the two tests, respectively.

Control animals:

yes

Details on study design:

Two control groups (one for each test) consisted of 11 and 12 female rats, respectively.

Oestrous cyclicity (parental animals):

Estrus cycle regularly studied by vaginal smear technique.

Postmortem examinations (parental animals):

SACRIFICE
- Maternal animals: All surviving animals were sacrificed on day 18 of gestation.
- Collected placentae were weighted together.

Postmortem examinations (offspring):

- Fetuses were counted postmortem and examined for stillbirth and malformation.
- Fetuses were weighted together.

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

Weight of the placenta was not significantly different between the experimental group and their respective control group.

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

effects observed, treatment-related

Description (incidence and severity):

Regarding the test without ZnSO4 gavage prior to mating, 12 out of 15 animals of the control group and the treated group were mated, of which 12 and 5 females, respectively, conceived during the study.
Regarding the test with ZnSO4 gavage prior to mating, 11 out of 18 animals of the control group and 15 out of 18 animals of the treated group were mated, of which 10 and 14 females, respectively, conceived during the study.

When zinc was first added to the food after coitus, the "implanation sites per pregnant female was lower in the zinc treated group (5.0) than in the control rats (7.0), however the difference was not significant (t-test). Implantation sites per mated female were 7.0 in the control group and 2.1 in the zinc fed experimental group."
When zinc treatment started 21 to 26 days prior to mating, there was no significant difference in incidentes of conception between the treated group and the control group. Also, there was no significant difference between the two groups regarding implantation sites expressed per mated or pregnant female. Also, the mean fetal and placental weights were similar.

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

concentration inducing effects

Effect level:

4 000 ppm

Based on:

element

Sex:

female

Basis for effect level:

other: see section "Decription of reproductive performance" and "details on results (P0)"

Remarks on result:

other: dosage of zinc for 21-26 day prior to mating

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

concentration inducing effects

Effect level:

4 000 ppm

Based on:

element

Sex:

female

Basis for effect level:

other: see section "Decription of reproductive performance" and "details on results (P0)"

Remarks on result:

other: no dosage of zinc prior to mating

Dose descriptor:

conc. level: oncentration inducing effects

Effect level:

200 mg/kg bw/day (nominal)

Based on:

element

Sex:

female

Basis for effect level:

other: "Other effect" as well as the descrption of the other effects (see above)

Remarks on result:

other: calculated based on default values (please refer to 'any other information on results incl. tables'

Critical effects observed:

no

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

No stillbirth or malformation of the fetuses for either of the tests was detected.

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Dose descriptor:

NOEC

Generation:

F1

Effect level:

4 000 ppm

Based on:

element

Sex:

male/female

Basis for effect level:

other: "Other effect" as well as the descrption of the other effects (see above)

Dose descriptor:

NOEC

Generation:

F1

Effect level:

200 mg/kg bw/day (nominal)

Based on:

element

Sex:

female

Basis for effect level:

other: "Other effect" as well as the descrption of the other effects (see above)

Remarks on result:

other: calculation based on default values (please refer to the field 'Any other information on results incl. tables'

Critical effects observed:

no

Reproductive effects observed:

no

Dose calculation

4000 ppm Zn in food/day = 4000 mg Zn/kg food/day = 4 mg Zn/g food/day

default values for dose calculation for female rats (according to Golde et al., 1984 and Paulussen et al., 1998, cited in ECHA Guidance R.8)

food consumption per day (female rat) = 17.5 g

body weight (female rat) = 0.35 kg

Zn intake per rat per day

4 mg Zn/g food/day x 17.5 g = 70 mg Zn/day

Zn intake per body weight/day

(70 mg Zn/day) / 0.35 kg = 200 mg/kg bw/day

The conversion factor from ppm to mg/kg bw/day for female rats is 0.05 (based on the calculation above and Lehman, A.J. (1954).

Conclusions:

For the female parent, the dose of 4,000 ppm zinc showed either no effects (in case of dosage start prior to mating) or a slight effect on reproduction performance (in case of dosage started after coitus).
For the F1 generation (examination of fetuses) no effect of the dosage of the female parent animal was observed.

Executive summary:

Anhydrous ZnSO4 was used to test the influence of zinc feeding on conception of rats. Two tests were conducted involving the dosing of female, virgin rats with zinc either after coitus or 21 to 26 days prior to mating. The dosage was continued during the pregnancy until the female rats were sacrificed on day 18 of gestation. Weight of the placenta was not significantly different between the experimental group and their respective control group. Regarding the test without ZnSO4 gavage prior to mating, 12 out of 15 animals of the control group and the treated group were mated, of which 12 and 5 females, respectively, conceived during the study.

In the test with ZnSO4 gavage prior to mating, 11 out of 18 animals of the control group and 15 out of 18 animals of the treated group were mated, of which 10 and 14 females, respectively, conceived during the study. When zinc was first added to the food after coitus, the "implanation sites per pregnant female was lower in the zinc treated group (5.0) than in the control rats (7.0), however the difference was not significant (t-test). Implantation sites per mated female were 7.0 in the control group and 2.1 in the zinc fed experimental group." When zinc treatment started 21 to 26 days prior to mating, there was no significant difference in incidents of conception between the treated group and the control group. Also, there was no significant difference between the two groups regarding implantation sites expressed per mated or pregnant female. Also, the mean fetal and placental weights were similar. No stillbirth or malformation of the fetuses for either of the tests was detected.  

For the female parent, the dose of 4,000 ppm zinc showed either no effects (in case of dosage start prior to mating) or a slight effect on reproduction performance (in case of dosage started after coitus). For the F1 generation (examination of fetuses) no effect of the dosage of the female parent animal was observed.

Reference 5

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:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 407 (Repeated Dose 28-day Oral Toxicity in Rodents)

Principles of method if other than guideline:

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.
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 in water at a volume of 1 ml/ 100g bw.
A 28-day oral feeding study was conducted rats with sodium gluconate at doses of 0, 1000, 2000 and 4100 mg/kg bw.
Repeated toxicity studies in Beagle dogs were conducted with sodium gluconate administered orally for 4 weeks at 500, 1000, 2000 mg/kg bw. doses.

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

oral: feed

Vehicle:

not specified

Details on exposure:

oral feeding

Duration of treatment / exposure:

28 days

Frequency of treatment:

once daily

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Dose / conc.:

2 000 mg/kg bw/day (actual dose received)

Dose / conc.:

4 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

10/sex/group

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: not specified
- Rationale for animal assignment (if not random): not specified
- Rationale for selecting satellite groups: not applicable
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale (if not random): not specified

Parental animals: Observations and examinations:

Repeated dose toxicity study with young adult unmated rats of both sexes
CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Not specified

BODY WEIGHT: Not specified

FOOD EFFICIENCY: Not specified

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Not specified

CLINICAL CHEMISTRY: Not specified

URINALYSIS: Not specified

NEUROBEHAVIOURAL EXAMINATION: Not specified

IMMUNOLOGY: Not specified

Oestrous cyclicity (parental animals):

not specified

Sperm parameters (parental animals):

not specified

Litter observations:

not applicable as no offsprings were generated

Postmortem examinations (parental animals):

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Postmortem examinations (offspring):

not applicable as no offsprings were generated

Statistics:

no data

Reproductive indices:

not examined

Offspring viability indices:

not examined

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:

not examined

Other effects:

not specified

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

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.

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

histopathology: non-neoplastic

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 repeated dose studies on sodium gluconate and with developmental toxicity studies on glucono-delta-lactone.

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.

Reference 6

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:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Qualifier:

no guideline followed

Principles of method if other than guideline:

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.
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 in water at a volume of 1 ml/ 100g bw.
A 28-day oral feeding study was conducted rats with sodium gluconate at doses of 0, 1000, 2000 and 4100 mg/kg bw.
Repeated toxicity studies in Beagle dogs were conducted with sodium gluconate administered orally for 4 weeks at 500, 1000, 2000 mg/kg bw. doses.

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Route of administration:

oral: gavage

Details on exposure:

feeding by gavage in water at a volume of 1 mL/100g bw.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

28 days

Frequency of treatment:

once daily

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Dose / conc.:

2 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

12/sex/group

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: not specified
- Rationale for animal assignment (if not random): not specified
- Rationale for selecting satellite groups: not applicable
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale (if not random): not specified

Parental animals: Observations and examinations:

Repeated dose toxicity study with young adult unmated rats of both sexes
CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Not specified

BODY WEIGHT: Yes / No / Not specified

FOOD EFFICIENCY:


OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Not specified

CLINICAL CHEMISTRY: Not specified
.
URINALYSIS: Not specified

NEUROBEHAVIOURAL EXAMINATION: Not specified

IMMUNOLOGY: Not specified

Oestrous cyclicity (parental animals):

not specified

Sperm parameters (parental animals):

not specified

Litter observations:

not applicable as no offsprings were generated

Postmortem examinations (parental animals):

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Postmortem examinations (offspring):

not applicable as no offsprings were generated

Statistics:

no data

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

Based on:

test mat.

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.

Sex:

female

Basis for effect level:

clinical signs

mortality

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

Critical effects observed:

no

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 repeated dose studies on sodium gluconate and with developmental toxicity studies on glucono-delta-lactone.

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.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 262.39 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

Effects on developmental toxicity

Description of key information

To address the endpoint developmental toxicity read-across on gluconates and derivatives and zinc 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. Besides publications on zinc and gluconate, public reports were studied to assess the developmental toxicity of zinc.

Assessment of Zinc toxicity in public reports

The following summaries have been adopted from Risk Assessment Reports (RARs) on zinc oxide (2008a) and zinc sulphate (2004):

“Developmental toxicity studies, according to a study design similar to OECD 414, with mice, rats, hamsters and rabbits were described with unspecified zinc sulphate. These studies do not permit the derivation of a proper NOAEL because neither reproductive nor developmental or maternal effects were observed, not even at the highest dose tested" .

“With respect to effects on reproduction, zinc deficiency is known to result in impairment of fertility and of foetal development. In humans additional zinc up to 0.3 mg Zn2+/kg bw/day during pregnancy did not result in adverse effects. Available data in animals on zinc excess indicate that adverse effects on fertility and foetal development may occur at dose levels of 200 mg Zn²⁺/kg bw/day, in conjunction with other effects such as perturbation of parental and foetal copper homeostasis. In humans a small disturbance (if any) of normal physiology, presumably indicative for copper deficiency, has been demonstrated at zinc excess of 50 and 150 mg Zn²⁺/day (0.83 and 2.5 mg Zn²⁺/kg bw/day, respectively), while 150 mg Zn²⁺/day (2.5 mg Zn²⁺/kg bw/day) resulted in clinical signs. As the margin between the dose at which in humans clinical signs are manifested and the dose at which in animals reproductive effects have been reported is so high (i.e. 80), it is considered unlikely that in humans reproductive effects will occur at exposure levels at which clinical signs do not manifest. Therefore, neither fertility nor developmental toxicity is considered endpoints of concern for humans. Based on the available information there is no reason to classify either metallic zinc or any of the zinc compounds considered for reproductive toxicity”

These statements are in line with those presented by the US Agency for Toxic Substances and Disease Registry (ATSDR, 2005) and WHO (2001).

Conclusively, the NOAEL for teratogenic effects is regarded to be 0.3 mg Zn/mg bw day as a worst-case value. This corresponds to a concentration of 1.89 mg/kg bw/day of the registered substance, when converting the NOAEL of elemental zinc to the registered substance under consideration of the molecular weight and the purity.

Data on zinc

The effect of zinc on reproduction toxicity was studied by Uriu-Hare et al. (1989). Starting on day 0 of gestation, rats were fed a low-Zn diet (4.5 mg/kg diet,1.42 mg ZnGHA/kg bw/day), an adequate-Zn diet (24.5 mg/kg diet, 7.732 mg ZnGHA/kg bw/day), or a high-Zn diet (500 mg/kg diet,157.8 mg ZnGHA/kg bw/day) throughout gestation. Fetuses were taken by cesarean section on gestation day 20. Maternal dietary Zn had a minor effect on fetal malformation frequency. The adequate- and high-Zn diets improved fetal length and weight.

Fetuses from dams fed the low-Zn diet had low liver Zn levels compared with those fed the adequate- and high-Zn diets. Maternal dietary Zn had an affect on fetal outcome. Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet. Fetuses receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses fed the low-Zn diet. No further improvement in calcification with the high-Zn diet was observed. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in group fed the high-Zn diet. Dietary Zn had only a modest effect on fetal malformation frequency, there wasno further improvement in the frequency of fetal abnormalities when the high-Zn diet was fed.

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.

 

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 zinc glucoheptonate, as the glucoheptonate-residue is also a derivative of gluconic acid. Therefore, no teratogenicity can be attributed to the glucoheptonate moiety of zinc glucoheptonate.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Principles of method if other than guideline:

The only available studies reported on the developmental toxicity for the gluconates of the category are for glucono-delta-lactone. These studies (unpublished) investigated teratogenicity following oral daily dosing of glucono-delta-lactone in in the rat, mouse, hamster and rabbit (Food & Drug Research Laboratories - Unpublished data (1973)).

GLP compliance:

not specified

Limit test:

no

Species:

hamster

Details on test animals or test system and environmental conditions:

no data available

Route of administration:

oral: unspecified

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: not specified

DIET PREPARATION - not specified

VEHICLE - not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not applicable, as already pregnant hamsters were used

Duration of treatment / exposure:

5 days (from day 6 to day 10 of gestation)

Frequency of treatment:

once daily

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

5.6 mg/kg bw/day (nominal)

Dose / conc.:

26 mg/kg bw/day (nominal)

Dose / conc.:

121 mg/kg bw/day (nominal)

Dose / conc.:

560 mg/kg bw/day (nominal)

No. of animals per sex per dose:

not specified

Control animals:

yes

Statistics:

not specified

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.

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.

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.

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/day for maternal and developmental toxicity (teratogenicity) was determined.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Principles of method if other than guideline:

Two studies were conducted in 1978 to assess the potential teratogenicity of GDL on rats (Fukuhara, K. 1978b) and mice (Fukuhara, K. 1978c).

GLP compliance:

not specified

Limit test:

no

Species:

mouse

Strain:

ICR

Details on test animals or test system and environmental conditions:

no data available

Route of administration:

oral: unspecified

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: not specified

DIET PREPARATION - not specified

VEHICLE - not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not applicable, as already pregnant mice were used

Duration of treatment / exposure:

10 days (from day 6 to day 15 of gestation)

Frequency of treatment:

once daily

Duration of test:

until postnatal day 21

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Dose / conc.:

4 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

not specified

Control animals:

yes

Maternal examinations:

general condition, body weight change or food consumption

Fetal examinations:

Some of 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.

Statistics:

not specified

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. Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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. Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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.

Basis for effect level:

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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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): Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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:

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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.

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. Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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.

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. Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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.

Reference 3

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Principles of method if other than guideline:

The only available studies reported on the developmental toxicity for the gluconates of the category are for glucono-delta-lactone. These studies (unpublished) investigated teratogenicity following oral daily dosing of glucono-delta-lactone in in the rat, mouse, hamster and rabbit (Food & Drug Research Laboratories - Unpublished data (1973)).

GLP compliance:

not specified

Limit test:

no

Species:

mouse

Strain:

CD-1

Details on test animals or test system and environmental conditions:

no data available

Route of administration:

oral: unspecified

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: not specified

DIET PREPARATION - not specified

VEHICLE - not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not applicable, as already pregnant mice were used

Duration of treatment / exposure:

10 days (from day 6 to day 15 of gestation)

Frequency of treatment:

once daily

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

6.95 mg/kg bw/day (nominal)

Dose / conc.:

32.5 mg/kg bw/day (nominal)

Dose / conc.:

150 mg/kg bw/day (nominal)

Dose / conc.:

695 mg/kg bw/day (nominal)

No. of animals per sex per dose:

not specified

Control animals:

yes

Statistics:

not specified

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.

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)

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.

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 dw/day. A NOAEL of > 695 mg/kg bw/day for maternal and developmental toxicity (teratogenicity) was determined.

Reference 4

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Principles of method if other than guideline:

The only available studies reported on the developmental toxicity for the gluconates of the category are for glucono-delta-lactone. These studies (unpublished) investigated teratogenicity following oral daily dosing of glucono-delta-lactone in in the rat, mouse, hamster and rabbit (Food & Drug Research Laboratories - Unpublished data (1973)).

GLP compliance:

not specified

Limit test:

no

Species:

rabbit

Strain:

Dutch

Details on test animals or test system and environmental conditions:

no data available

Route of administration:

oral: unspecified

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: not specified

DIET PREPARATION - not specified

VEHICLE - not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not applicable, as already pregnant rabbits were used

Duration of treatment / exposure:

13 days (from day 6 to day 18 of gestation)

Frequency of treatment:

once daily

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

7.8 mg/kg bw/day (nominal)

Dose / conc.:

36.2 mg/kg bw/day (nominal)

Dose / conc.:

168.5 mg/kg bw/day (nominal)

Dose / conc.:

780 mg/kg bw/day (nominal)

No. of animals per sex per dose:

not specified

Control animals:

yes

Statistics:

not specified

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.

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.

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.

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.

Reference 5

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Principles of method if other than guideline:

The only available studies reported on the developmental toxicity for the gluconates of the category are for glucono-delta-lactone. These studies (unpublished) investigated teratogenicity following oral daily dosing of glucono-delta-lactone in in the rat, mouse, hamster and rabbit (Food & Drug Research Laboratories - Unpublished data (1973)).

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

no data available

Route of administration:

oral: unspecified

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: not specified

DIET PREPARATION - not specified

VEHICLE - not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not applicable, as already pregnant rats were used

Duration of treatment / exposure:

10 days (from day 6 to day 15 of gestation)

Frequency of treatment:

once daily

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

5.94 mg/kg bw/day (nominal)

Dose / conc.:

27.6 mg/kg bw/day (nominal)

Dose / conc.:

128 mg/kg bw/day (nominal)

Dose / conc.:

594 mg/kg bw/day (nominal)

No. of animals per sex per dose:

not specified

Control animals:

yes

Statistics:

not specified

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.

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)

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.

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.

Reference 6

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable well documented peer-reviewed report.

Principles of method if other than guideline:

Two studies were conducted in 1978 to assess the potential teratogenicity of GDL on rats (Fukuhara, K. 1978b) and mice (Fukuhara, K. 1978c).

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

no data available

Route of administration:

oral: unspecified

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: not specified

DIET PREPARATION - not specified

VEHICLE - not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not applicable, as already pregnant rats were used

Duration of treatment / exposure:

10 days (from day 6 to day 15 of gestation)

Frequency of treatment:

once daily

Duration of test:

until postnatal day 21

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Dose / conc.:

4 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

not specified

Control animals:

yes

Maternal examinations:

general condition, body weight change or food consumption

Fetal examinations:

Some of 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.

Statistics:

not specified

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 fetuses, 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 fetuses. 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.

Basis for effect level:

body weight and weight gain

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

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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): Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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):

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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:

Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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.

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.

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 was 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. Protraction of the duration of pregnancy or abnormalities at birth were not observed in the dams allowed to deliver spontaneously, 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.

Reference 7

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Starting on day 0 of gestation, streptozocin-induced diabetic and nondiabetic control rats were fed a low-Zn diet (4.5 µg/g diet), an adequate-Zn diet (24.5 µg/g diet), or a high-Zn diet (500 µg/g diet) throughout gestation. Fetuses were taken by cesarean section on gestation day 20 and examined

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen, Gilroy, CA
- Females: virgins
- Weight at study initiation: (P1) Females: 220-240 g
- Housing: housed individually in suspended stainless steel cages
- Diet: ad libitum
- Water: ad libitum (deionised water)
- Acclimation period: adaption to diet and light-dark cycle for 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-23 °C
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: feed

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentrations of Zn, Cu, Mn, Fe, Mg and Ca were confirmed by flame atomic acsorption spectroscopy (AAS IL-551, Instrumentation Laboratories, Wilmington, MA).

Details on mating procedure:

- M/F ratio per cage: not specified
- Length of cohabitation: not specified
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

After mating, the rats were assigned to one of the following diets ad libitum:
1) low Zn diet containing 4.5 µg/g diet
2) adequate Zn diet containing 24.5 µg/g diet
3) high Zn diet containing 500 µg/g diet.

Frequency of treatment:

daily with food

Duration of test:

20 days

Dose / conc.:

4.5 other: µg/g diet

Remarks:

further referred to as "low-Zn diet"

Dose / conc.:

24.5 other: µg/g

Remarks:

further referred to as "adequate-Zn diet"

Dose / conc.:

500 other: µg/g diet

Remarks:

further referred to as "high-Zn diet"

No. of animals per sex per dose:

not mentioned in publication

Control animals:

no

Details on study design:

This study was designed to assess the effect of maternal Zn intake in diabetes-induced rats. For this WoE, only the results of the diabetes' control group is of interest. Consequently, the results of the diabetes group will be not discussed herein.

Maternal examinations:

BODY WEIGHT: Yes
- Time schedule for examinations: daily

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined on a daily basis

Ovaries and uterine content:

placenta was examined after termination: Yes
- Placental weight: Yes
- Number of implantations: Yes
- Total resorption (%)

Fetal examinations:

- maternal and fetal blood and plasma parameters were examined
-fetal liver was analysed for metallothionein concentration

- External examinations: Yes
Fetal length (cm)
Fetal wt (g)

- Skeletal examinations: Yes
Ossification centers
Sternum
Caudal vertebrae
Metacarpals
Anterior phalanges

Statistics:

Data were analyzed with two-way analysis of variance. The significance of observed differences among the groups was evaluated with Duncan's multiple-range test. Values of P < .05 were considered statistically significant.

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

"Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal weight gain in the diabetic groups."

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups,

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Increasing dietary Zn tended to lower the resorption frequency.

Number of abortions:

not specified

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

effects observed, treatment-related

Description (incidence and severity):

Overall, diabetic dams had fewer live pups and more resorptions per litter compared with control dams. Increasing dietary Zn tended to lower the resorption frequency in the diabetic and control groups, although this did not reach statistical significance. The total number of implantation sites per dam were similar among groups.

Early or late resorptions:

effects observed, treatment-related

Description (incidence and severity):

Increasing dietary Zn tended to lower the resorption frequency in the diabetic and control groups, although this did not reach statistical significance.

Dead fetuses:

effects observed, treatment-related

Description (incidence and severity):

Increasing dietary Zn tended to lower the resorption frequency in the diabetic and control groups, although this did not reach statistical significance.

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

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

4.5 mg/kg diet

Based on:

element

Basis for effect level:

other: resorption frequency

Remarks on result:

other: "low -Zn diet

Dose descriptor:

conc. level: see 'Remarks'

Remarks:

test concentration

Effect level:

24.5 mg/kg diet

Based on:

element

Basis for effect level:

other: resorption frequency

Remarks on result:

other: "adequate Zn-diet"

Dose descriptor:

conc. level: see 'remarks'

Remarks:

test concentration

Effect level:

500 mg/kg diet

Based on:

element

Basis for effect level:

other: resorption frequency

Remarks on result:

other: "high-Zn diet"

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

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 length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet.

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

External malformations:

effects observed, treatment-related

Description (incidence and severity):

Dietary Zn had only a modest effect on fetal malformation frequency. Although the percentage of abnormalities was five times higher in the low-Zn control group than in the adequate-Zn group, this was due to a change in the malformation frequency from ca. 1 % (1 of 107) to 5% (5 of 101).

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

Fetuses from control dams receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses from control dams fed the low-Zn diet. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in the control group fed the high-Zn diet.

Visceral malformations:

not examined

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet.
In the controls, dietary Zn had only a modest effect on fetal malformation frequency. Although the percentage of abnormalities wasfive times higher in the low-Zn control group than in the adequate-Zn group, this was due to a change in the malformation frequency from - 1 % (1 of 107) to 5% (5 of 101).

Dose descriptor:

conc. level: test concentration

Effect level:

4.5 mg/kg diet

Based on:

element

Sex:

not specified

Basis for effect level:

other: body length, Ossification of fetal vertebrae, fetal malformation frequency

Dose descriptor:

conc. level: test concentration

Effect level:

24.5 mg/kg diet

Based on:

element

Sex:

not specified

Basis for effect level:

other: body length, Ossification of fetal vertebrae, fetal malformation frequency

Dose descriptor:

conc. level: test concentration

Effect level:

500 mg/kg diet

Based on:

element

Sex:

not specified

Basis for effect level:

other: body length, Ossification of fetal vertebrae, fetal malformation frequency

Abnormalities:

no effects observed

Developmental effects observed:

no

Table 1: Effect of dietary Zn on outcome, skeletal development, and malformation frequency of fetuses from Sprague-Dawley rats

	Low Zn	Adequate Zn	High Zn
Litters(n)	9	9	8
Live fetuses/litter	11.2±1.5*+	11.9± 1.5*+	12.5±0.9+
Implantation sites/litter	12.9±1.4	12.7±1.5	13.1±0.7
Fetal length (cm)	3.75±0.03*	3.90± 0.02+	3.91±0.02+
Fetal wt (g)	3.27±0.06*	3.80±0.05+	3.75±0.04+
Placental wt (g)	0.48±0.01*	0.49±0.01*	0.48±0.01*
Resorptions/litter	1.67± 0.85*+	0.78±0.32*	0.63±0.26*
Total resorption(%)	12.9*	6.1 +	4.8+
Total resorption/total implantation sites	15/116	7/114	5/105
Fetuses studied for skeletal ossification (n)	96	103	98
Ossification centers
Sternum	5.15±0.13P	5.79± 0.05#	5.83± 0.06#
Caudal vertebrae	5.22±0.14P	6.08± 0.06#	6.02±0.08#
Metacarpals	3.73±0.05P	3.96± 0.02#	3.95± 0.02#
Anterior phalanges	1.10± 0.1P	1.67± 0.09#	1.68± 0.08#
Total malformations(%)	4.9P	0.9#	0.0#
Malformations/fetuses	5/101	1/107	0/100

Values are means ± SE. Means not sharing a common superscript are significantly different at P< 0.05.

Conclusions:

Maternal animal:
"Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal
weight gain in the diabetic groups."Increasing dietary Zn tended to lower the resorption frequency. No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups,

Fetuses:
„Fetuses from dams fed the low-Zn diet had low liver Zn levels compared with those fed the adequate- and high-Zn diets. Maternal dietary Zn had an affect on fetal outcome. Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet. Fetuses receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses fed the low-Zn diet. No further improvement in calcification with the high-Zn diet was observed. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in group fed the high-Zn diet. Dietary Zn had only a modest effect on fetal malformation frequency, there was no further improvement in the frequency of fetal abnormalities when the high-Zn diet was fed."

Executive summary:

Starting on day 0 of gestation, rats were fed a low-Zn diet (4.5 mg/kg diet), an adequate-Zn diet (24.5 mg/kg diet), or a high-Zn diet (500 mg/kg diet) throughout gestation. Fetuses were taken by cesarean section on gestation day 20. Maternal dietary Zn had a minor effect on fetal malformation frequency. The adequate- and high-Zn diets improved fetal length and weight.

Maternal animal:

"Among the control groups, dams fed the low-Zn diet had significantly less body weight gain on days 18-20 of pregnancy than controls fed the adequate- or high-Zn diets. There was no effect of dietary Zn on maternal weight gain in the diabetic groups."Increasing dietary Zn tended to lower the resorption frequency. No diet-related differences in the concentrations of liver and kidney Mn, Cu, Zn, Ca, or Mg were found. Dietary Zn did not affect maternal kidney metallothionein concentrations. As dietary Zn increased, plasma Zn concentrations also increased. Placental concentrations of Cu, Zn, Fe, and Ca were similar among the groups.

 

Fetuses:

„Fetuses from dams fed the low-Zn diet had low liver Zn levels compared with those fed the adequate- and high-Zn diets. Maternal dietary Zn had an affect on fetal outcome. Fetal length was shortest in the low-Zn group. With the adequate-Zn diet, linear growth was increased. However, there was no further improvement in length with the high-Zn diet. Fetuses receiving the adequate-Zn diet had 11% more calcified sternal sites than fetuses fed the low-Zn diet. No further improvement in calcification with the high-Zn diet was observed. Ossification of fetal vertebrae, metacarpals, and anterior phalanges was lowest in the low-Zn group and increased compared with fetuses from the adequate-Zn group. Ossification of these three sites did not improve in group fed the high-Zn diet. Dietary Zn had only a modest effect on fetal malformation frequency, there was no further improvement in the frequency of fetal abnormalities when the high-Zn diet was fed."

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1.89 mg/kg bw/day

Species:

other: human

Quality of whole database:

The quality of the whole database is considered sufficient for estimation ofthe developmental 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

Toxicity to reproduction: other studies

Description of key information

The following human data regarding the effects of zinc supplementation during pregnancy provide further evidence that zinc compounds are not teratogenic.

human data

Data on zinc sulphate (Mahmoud et al, 1989)

The objective of this study was to see whether zinc supplementation during pregnancy improves maternal and fetal outcome. The prospective study started at booking and continued till discharge of mother and baby from the maternity hospital. Mothers were randomly assigned to receive zinc supplementation or placebo in a double blind trial. Women booking before 20 weeks of gestation who agreed to take part in the study were the test subjects. A total of 494 mothers were followed up till the end of pregnancy. There was no difference between the groups given zinc and placebo in their social or medical backgrounds.

Mothers in the active treatment group received one capsule of 20 mg elemental zinc daily and those in the placebo treated group a capsule identical in appearance and taste with the active capsule but which contained inert substances. Various adverse outcomes were tested, including maternal bleeding, hypertension, complications of labour and delivery, gestational age, Apgar scores, and neonatal abnormalities. The main outcome measure was birth weight.

There were no differences whatsoever between mothers given a zinc supplement and those given a placebo. Zinc supplementation in pregnancy in the United Kingdom does not seem to offer any benefits to the mother or her fetus.

The tested concentration of 20 mg elemental zinc per day did not show adverse effects, either. Therefore, a concentration of 20 mg/d can be regarded as NOEL, which corresponds to a NOEL of 126.26 mg/d and 2.1 mg/kg bw/day (person of 60 kg) for zinc glucoheptonate.

Data on Zinc aspartate (Kynast and Saling, 1986) and zinc citrate (Simmer et al. 1991) (please refer to 'Exposure related observations in human')

The beneficial effects of the oral application of zinc aspartate in pregnancy is investigated in a randomly selected study group of 179 patients and a control group of 345 patients (Kynast and Saling, 1986). This study confirms the prophylactic effectiveness of zinc replacement in reducing the overall complication rate for both mother and fetus and in particular for large-for-date and small-for-date infants. The therapy is well tolerated and accepted by the patients and causes no side effects. The results are in line with those of other working groups reporting on zinc as an important element with protective effects on fetal growth and development in pregnancy.The results of this study can be summarized as follows: (1) Maternal and fetal complications occur less often in both pregnancy and labor in patients who received zinc therapy; (2) the incidence of both large-for-date (LFD) and small for date (SFD) infants is reduced with zinc therapy; (3) oral zinc therapy is well tolerated and accepted by the patients and caused no deleterious side effects. The applied dose of 20 mg zinc aspartate/day corresponds to a concentration of 25.2 ZnGHA/day.

A double-blind randomised trial of oral zinc supplementation was carried out during the last two trimesters of pregnancy (Simmer et al. 1991). Fifty-six women at risk of delivering a small-for-gestational-age baby received either zinc citrate (22.5 mg daily) or placebo. Twenty-nine of the women were compliant. Zinc significantly reduced the incidence of intrauterine growth retardation, and most measured indices of labour and fetal health were better in the supplemented group. Side-effects were generally no more frequent in the supplemented group than in the placebo group, but the three patients with vomiting were taking Zn. No adverse effects of Zn therapy were found.

The analysis of existing metabolism data of gluconate and glucoheptonate moieties allow to conclude that toxicity effects of the target substance glucoheptonate-Zn complex can be predicted by using the toxicological data of structurally related gluconate complexes with the same metals.Therefore, these results are also relevant for zinc glucoheptonate. The applied dose of 22.5 mg zinc citrate/day corresponds to a concentration of 15.62 ZnGHA/day.

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1985-1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

One capsule containing either 20 mg elemental zinc or a placebo capsule containing inert substances was taken daily for breakfast. 246 women received the zinc supplementation, 248 were given the placebo. The women were less than 20 weeks pregnant at the beginning of the study. They took one capsule (either zinc supplement or a placebo) daily, until they delivered.

GLP compliance:

no

Type of method:

in vivo

Specific details on test material used for the study:

capsules containing 66 mg zinc sulphate (corresponding to 20 mg elemental zinc) were prepared by Smith Kline and French Ltd.

Species:

other: human

Sex:

female

Details on test animals or test system and environmental conditions:

Women who were less than 20 weeks pregnant were allowed to participate in the study. "There were no differences in their social and biological backgrounds. They were of similar age and had similar obstetric histories. No differences in maternal weight, blood pressure measurements, or haemoglobin, ferritin, or leucocyte zinc concentrations were present at the time of enrollment. The proportion of smokers within both groups was similar as was the prevalence of a history of nausea or vomiting and of urinary infections."

Route of administration:

oral: capsule

Details on exposure:

One capsule containing either 20 mg elemental zinc or a placebo capsule containing inert substances was taken daily for breakfast.
If supplements were prescribed, patients were advised to take the iron and folate tablet in the evening and to avoid taking the iron und study capsule together.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

The women were less than 20 weeks pregnant at the beginning of the study. They took one capsule (either zinc supplement or a placebo) daily, untill they delivered.

Frequency of treatment:

daily one capsule for breakfast

Dose / conc.:

20 other: mg/d

Remarks:

elemental zinc

No. of animals per sex per dose:

246 women received the zinc supplementation, 248 were given the placebo.

Control animals:

yes, concurrent vehicle

Details on study design:

"Enough capsules were provided to last till the next hospital visit. The mothers were seen by the research midwife at the 28-32 week visit and again on the day after delivery. At each visit information was obtained about the use of any other drugs or iron or vitamin supplementation. Compliance was assessed by the regularity with which the study capsules were taken. Those who took the supplement daily or on most days were grouped as compliers, and the rest were regarded as non-compliers. At the 28-32 week visit the mothers were asked to complete a seven day dietary diary."

Statistics:

"Information on outcome was coded by a person who did not participate in the clinical care of the woman, and the data were analysed with the statistical package for the social sciences (SPSS-X) and the biomedical programs data package. Comparison of frequencies was by the chi² test with Yates's correction where appropriate. When numbers were very small Fisher's exact test was employed. t Tests were used to compare means and the Mann-Whitney U test to compare median values. Statistical significance was taken at the 5% level. Though the study was designed to look at beneficial effects, we were also keen to examine adverse outcomes, so two tailed tests were used."

Dose descriptor:

NOEC

Effect level:

20 other: mg/d

Based on:

element

Sex:

female

Basis for effect level:

other: fetus and neonatas properties, e.g. birth weight, mean head circumference, ...

Dose descriptor:

NOEC

Effect level:

0.3 mg/kg bw/day

Based on:

element

Sex:

female

Basis for effect level:

other: fetus and neonatas properties, e.g. birth weight, mean head circumference, ...

Remarks on result:

other: converted to mg/kg bw/day for a person of 60 kg

"There were no differences in outcome between the groups (table 1). In particular there was no evidence of a lower incidence of growth retardation or neonatal abnormalities in the zinc treated group. The condition of the infant at birth was identical in the two groups. There were three perinatal deaths in each group. In all, however, six pregnancies had either been terminated or ended in spontaneous abortion during the study, but the difference in distribution between the groups (one case in the zinc treated group, five cases in the control group) did not approach significance."

Table 1: Details of fetuses and neonates in the two groups. Except where stated otherwise figures are numbers (percentages) of fetuses/neonates.

		Zinc supplementation group	Placebo supplementation group
		(n = 248*)	(n = 249*)
Sex:	Male	118/247 (48)	116/245 (47)
	Female	129/247 (52)	129/245 (53)
Birth weight (g):	Median	3390 (n=247)	3370 (n = 244)
	Mean (SD)	3291 (581)	3319 (531)
	< 2500	15/247 (6)	13/244 (5)
	2500 - 3499	140/247 (57)	135/244 (55)
	≥ 3500	92/247 (37)	96/244 ( 39)
Congenital defects		5/248 (2)	8/249 (3)
Other abnormalities		34/248 (14)	47/249 (19)
Apgar scores:	1 minute < 6	16/244 (7)	22/243 (9)
	1 minute ≥ 6	228/244 (93)	221/243 (91)
	5 minutes < 8	7/243 (3)	8/243 (3)
	5 minutes ≥ 8	236/243 (97)	235/243 (97)
Outcome:	Stillbirth/died	3/248 (1)	3/249 (1)
	Alive	244/248 (98)	241/249 (97)
	Terminated/miscarried	1/248 (0)	5/249 (2)
	Median zinc concentrations in cord blood (µmol/10^10cells)	l-36(n = 131)	1-38 (n = 116)

* Two twin pregnancies occured in the zinc supplementation group and one in the controls.

Executive summary:

The objective of this study was to see whether zinc supplementation during pregnancy improves maternal and fetal outcome. The prospective study started at booking and continued till discharge of mother and baby from the maternity hospital. Mothers were randomly assigned to receive zinc supplementation or placebo in a double blind trial. Women booking before 20 weeks of gestation who agreed to take part in the study were the test subjects. A total of 494 mothers were followed up till the end of pregnancy. There was no difference between the groups given zinc and placebo in their social or medical backgrounds.

Mothers in the active treatment group received one capsule of 20 mg elemental zinc daily and those in the placebo treated group a capsule identical in appearance and taste with the active capsule but which contained inert substances. Various adverse outcomes were tested, including maternal bleeding, hypertension, complications of labour and delivery, gestational age, Apgar scores, and neonatal abnormalities. The main outcome measure was birth weight.

There were no differences whatsoever between mothers given a zinc supplement and those given a placebo. Zinc supplementation in pregnancy in the United Kingdom does not seem to offer any benefits to the mother or her fetus.

The tested concentration of 20 mg elemental zinc per day (=0.3 mg/kg bw/day for a person of 60 kg) did not show adverse effects, either. Therefore, a concentration of 20 mg/day (=0.3 mg/kg bw/day for a person of 60 kg) can be regarded as NOEL.

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 zinc sulfate, zinc acetate, elemental Zinc and gluconates and derivatives caused no reproductive toxicity and no teratogenicity in the rats and dogs in the available toxicity studies. The NOAEL of zinc glucoheptonate after oral application was calculated from the source substance zinc sulfate. The NOAEL for reproductive toxicity was 1262.39 mg/kg bw/day. The NOAEL for developmental toxicity was regarded to be 1.89 mg/kg bw/day as a worst-case value derived with data on human exposure.

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