Sodium salicylate

Endpoint summary

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Effects on fertility

Description of key information

Reproductive Toxicity

NOAEL was considered to be 80 mg/kg/day when pregnant female Sprague Dawley rats were treated with the test chemical by oral gavage. LOAEL was considered at 200 mg/kg bw/day based on increased labor duration and increased maternal perinatal lethality.

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction

Remarks:

other: one-generation study

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from a peer reviewed journal.

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Pregnant rats were exposed to the test chemical during gestation to investiagte potential toxicological effects on reproduction and development.

GLP compliance:

not specified

Limit test:

no

Justification for study design:

No data available

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

No data available

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 63 days
- Weight at study initiation: 182-263 g
- Housing: Animals were housed individually under controlled conditions of temperature, humidity and lighting.
- Diet (e.g. ad libitum):Certified Rodent Chow 5002 were provided ad libitum
- Water (e.g. ad libitum):ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C):21.11±1.2 °C
- Humidity (%):57±3.8%
- Photoperiod (hrs dark / hrs light):12-h light/dark

Route of administration:

oral: gavage

Vehicle:

other: 0.5 % Aqueous methyl cellulose

Details on exposure:

Test chemical was administered by oral gavage in 0.5% aqueous methyl cellulose from day 15 to 21 of gestation. One half of the dose was given to the animals on the morning and the second half 6-8 hours later.

VEHICLE
- Justification for use and choice of vehicle (if other than water): Test chemical was soluble in 0.5% aqueous methyl cellulose.
- Concentration in vehicle: 0, 20, 80 or 200 mg/kg bw/day
- Amount of vehicle (if gavage): Dosing volume was 10 ml/kg per dosing occasion.
- Other: One-half of the dose was given to the animals in the morning and the second half 6-8 h later.

Details on mating procedure:

- M/F ratio per cage: One female and one male (1:1)
- Length of cohabitation: Until confirmed pregnancy
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy: The occurrence of copulation was determined by daily inspection for a copulatory plug.The day at which evidence of mating was detected was designated gestation day 0.
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility: No data available
- Further matings after two unsuccessful attempts: [no / yes (explain)]: No
- After successful mating each pregnant female was caged (how):Female was placed in an individual cage.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Gestation day 15 to 21.

Frequency of treatment:

Twice daily. One half of the dose was given in the morning and the second half 6-8 hours later.

Details on study schedule:

F0: Pregnant female rats were randomly assigned to one of three treatment groups which consisted of 25 females and received 0, 20, or 80 mg/kg/day of the test chemical or to one treatment group consisting of 16 females which received 200 mg/kg/day of the test chemical. All rats were given the respective dosage via gavage on days 15 through 21 of gestation twice daily. Beginning of day 21, the animals were observed hourly for the onset of labor. All surviving F0 females were euthanized by carbon dioxide inhalation at lactation day 1. On gestation day 25, those females which failed to deliver were euthanized. The uterus and ovaries of all dams were exposed by an abdominal incision and grossly examined to determine the number of implantation sites present.
F1: As soon as possible after delivery, all pups were examined for external abnormalities and the number of viable and nonviable pups was recorded for each female. Pups were sexed and weighed individually on lactation day 0. All pups were then euthanized by carbon dioxide inhalation at lactation day 1.

Remarks:

Doses / Concentrations: 0, 20, or 80 or 200 mg/kg/day

No. of animals per sex per dose:

Total:86
Control:25 females
20 mg/kg/day: 25 females
80 mg/kg/day: 25 females
200 mg/kg/day: 16 females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Doses were determined in pilot study using an identical protocol which yielded an effect level of 200 mg/kg/day and a NOEL of less than 100mg/kg/day for oral exposure to the test chemical.
- Rationale for animal assignment (if not random): Animals were randomly assigned to one of three treatment groups which consisted of 25 females and received either 0, 20, or 80 mg/kg/day test chemical or one of two treatment groups which consisted of 16 females and received 200 mg/kg/day of chemical.

Parental animals: Observations and examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: yes

DETAILED CLINICAL OBSERVATIONS: Yes
Time schedule: The animals were observed twice daily throughout the study for mortality and signs of overt toxicity.

BODY WEIGHT: Yes
Time schedule for examinations: Individual body weights were recorded on gestation days 0, 6, 15, 16, 17, 18, 19, 20 and 21

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No
Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: no
Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
Time schedule for examinations:

OTHER: No Data Available

Oestrous cyclicity (parental animals):

Not examined

Sperm parameters (parental animals):

Not examined

Litter observations:

Litters were examined for numbers of live and stillborn pups and gross abnormalities. The pups were sexed and weighed individually on lactation day 0.

Postmortem examinations (parental animals):

UTERUS:
The uterus and ovaries of all dams were exposed by an abdominal incision and grossly examined to determine the number of implantation sites present.

Postmortem examinations (offspring):

No data available

Statistics:

It is indicated in the study, the data was subjected to statistical analysis.The methods used included Bartlett’s test for homogeneity of variance. Comparisons were made by one-way analysis of variance (ANOVA). Pairwise comparisons were made using the appropriate t-test (for equal and unequal variance) or pairwise comparisons were made with a Bonferroni correction to determine the significance.

Reproductive indices:

No data available

Offspring viability indices:

No data available

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical signs of maternal physical distress during parturition included labored breathing, decreased activity, and blood staining in the abdominal, nasal, and oral areas. No evidence of increased maternal distress was noted in animals from either the mid-dose (80 mg/kg/day) or low-dose (20 mg/kg/day).

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

The incidence of maternal perinatal death was significantly increased at 200 mg/kg compared to the control group. That is, 4 of 10 animals at 200 mg/kg died or had to be sacrificed due to extreme distress whilst only 1 of 21 animals treated at 0 mg/kg died perinatally. At 20 or 80 mg/kg/day, no evidence of increased peripatum mortality was noted.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No effects on gestational body weight gain.

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

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):

No observations of adverse effects until the onset of parturition at 0, 20 or 80 mg/kg/day. Both onset of labor and its duration were disrupted in the animals receiving the highest dose (200 mg/kg). Labor times in these groups ranged from 1-14 h with a mean duration of 3.6 h for the chemical-treated animals. Mean gestational length was measured at 21.5 days for the control animals. A dose-related delay in labor onset was observed for the animals treated with test chemical, however, no statistical variation from control animals was observed at any of the individual doses.

Key result

Dose descriptor:

NOAEL

Effect level:

>= 80 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

reproductive performance

Key result

Dose descriptor:

LOAEL

Effect level:

<= 200 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

mortality

reproductive performance

Clinical signs:

not specified

Dermal irritation (if dermal study):

not examined

Mortality / viability:

mortality observed, non-treatment-related

Description (incidence and severity):

A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg).

Body weight and weight changes:

no effects observed

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

Anogenital distance (AGD):

not examined

Nipple retention in male pups:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

No external visible abnormalities were observed in any of the pups that survived delivery. Gross examination was not performed on fetuses that died peripartum.

Histopathological findings:

not specified

Other effects:

no effects observed

Description (incidence and severity):

No significant effects were observed on mean pups per litter, live pups per litter, mean pup weight, or sex ratio..

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

>= 200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

mortality

body weight and weight gain

gross pathology

other: mean pups per litter, live pups per litter, sex ratio

Reproductive effects observed:

not specified

Treatment related:

not specified

I] Fetal observations in offspring of Sprague-Dawley rats treated orally with the test chemical on days 15-21 of gestation.

 

	Control	Test Chemical
	0 mg/kg/day	20 mg/kg/day	80 mg/kg/day	200 mg/kg/day
Litters with livebom pups	20	20	18	6
Pups delivered (total)	255	270	230	62
Mean pups/litter	12.75 ± 3.82	13.50 ± 2.80	12.78 ± 3.08	10.33 ±4.46
Stillborn pups	8	7	1	6
Live pups/litter
Lactation day 0	12.35 ±3 .82	13.15 ±2.66	12.72 ±3.04	9.33 ± 4.76
Lactation day 1	12.30 ±3.88	13.15 ± 2.66	12.72 ±3.04	8.67 ±5.32
Mean pup weight (g)	5.84 ±0.62	5.70 ± 0.52	5.85 ± 0.49	5.23 ± 0.23
Pups dying, missing, and/or cannibalized
Lactation day	0	0	0	2
Lactation day	1	0	0	2
Sex ratio (male pups:total pups)	55.1	47.5	50.2	51.8

 

  II] Maternal and reproductive observations in Sprague-Dawley rats treated orally with the test chemicals on days 15-21 of gestation.

 

	Control	Test chemical
	0 mg/kg/day	20 mg/kg/day	80 mg/kg/day	200 mg/kg/day
Number of females mated	25	25	25	I6
Number of females pregnant	21	20	18	10
Mean gestational weight change (g)”	133.6 ± 20.3	136.9 ±1 9.8	135.1 ±18.8	131.7 ±9.7
Females with liveborn pups	20	20	18	6
Gestation Index	95.2	100	100	60
Females surviving delivery	20	20	18	6*

 

 

Conclusions:

NOAEL was considered to be 80 mg/kg/day when pregnant female Sprague Dawley rats were treated with the test chemical by oral gavage. LOAEL was considered at 200 mg/kg bw/day based on increased labor duration and increased maternal perinatal lethality.

Executive summary:

Pregnant female rats were treated with the test chemical by oral gavage at 0, 20, 80 and 200 mg/kg bw/day from day 15 to 21 of gestation. Twenty-five rats were used per dose level up to 80 mg/kg whereas sixteen rats were used at 200 mg/kg. No significant effects were observed on gestational body weight gain and no signs of toxicity were observed until onset of delivery. Treatment at 200 mg/kg resulted in a significant increase in labor duration compared to control data (mean, ≈3.5 hours at 200 mg/kg vs. mean, ≈1.2 hours at 0 mg/kg). Gestation length was unaffected by treatment. A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg). No significant effects were observed on mean pups per litter, live pups per litter, mean pup weight, or sex ratio. No external visible abnormalities were observed in any of the pups that survived delivery. Gross examination was not performed on fetuses that died peripartum. The incidence of maternal perinatal death was significantly increased at 200 mg/kg compared to the control group. That is, 4 of 10 animals at 200 mg/kg died or had to be sacrificed due to extreme distress whilst only 1 of 21 animals treated at 0 mg/kg died perinatally. NOAELwas considered to be 80 mg/kg/day when pregnant female Sprague Dawley rats were treated with the test chemical by oral gavage. LOAEL was considered at 200 mg/kg bw/day based on increased labor duration and increased maternal perinatal lethality.

Effect on fertility: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

80 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The data is K2 level as the data has been obtained from an experimental study from the reliable journal.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Reproductive Toxicity

Pregnant female rats were treated with the test chemical by oral gavageat 0, 20, 80 and 200 mg/kg bw/day from day 15 to 21 of gestation. Twenty-five rats were used per dose level up to 80 mg/kg whereas sixteen rats were used at 200 mg/kg. No significant effects were observed on gestational body weight gain and no signs of toxicity were observed until onset of delivery. Treatment at 200 mg/kg resulted in a significant increase in labor duration compared to control data (mean, ≈3.5 hours at 200 mg/kg vs. mean, ≈1.2 hours at 0 mg/kg). Gestation length was unaffected by treatment. A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg). No significant effects were observed on mean pups per litter, live pups per litter, mean pup weight, or sex ratio. No external visible abnormalities were observed in any of the pups that survived delivery. Gross examination was not performed on fetuses that died peripartum. The incidence of maternal perinatal death was significantly increased at 200 mg/kg compared to the control group. That is, 4 of 10 animals at 200 mg/kg died or had to be sacrificed due to extreme distress whilst only 1 of 21 animals treated at 0 mg/kg died perinatally. NOAEL was considered to be 80 mg/kg/day when pregnant female Sprague Dawley rats were treated with the test chemical by oral gavage. LOAEL was considered at 200 mg/kg bw/day based on increased labor duration and increased maternal perinatal lethality.

Effects on developmental toxicity

Description of key information

Developmental Toxicity

NOAEL for developmental toxicity was considered at ≥200 mg/kg bw/day in pregnant female rats follwoing exposure to the test chemical from gestation day 15 to 21.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from a peer reviewed journal

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Pregnant rats were exposed to the test chemical during gestation to investiagte potential toxicological effects on reproduction and development.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

Details on test animals and env. conditions
TEST ANIMALS
- Source: Charles River Laboratories
(Portage, MI).
- Age at study initiation: 63 days
- Weight at study initiation: 182-263g
- Fasting period before study: No data available

- Housing: The animals were housed individually
- Use of restrainers for preventing ingestion (if dermal): yes/no
- Diet (e.g. ad libitum): Food (Certified Rodent
Chow 5002, Purina Mills, Inc., St. Louis, MO) ad libitum
.
- Water (e.g. ad libitum): water were provided ad libitum
- Acclimation period: No data available


ENVIRONMENTAL CONDITIONS
- Temperature (°C):21.11±1.2 °C
- Humidity (%):57±3.8%
- Air changes (per hr): No data available

- Photoperiod (hrs dark / hrs light): No data available


IN-LIFE DATES: From: To:

Route of administration:

oral: gavage

Vehicle:

other: 0.5% aqueous methyl cellulose

Details on exposure:

Details on exposure
PREPARATION OF DOSING SOLUTIONS:
Test chemical was mixed with 0.5% aqueous methyl cellulose to form dosing solution
DIET PREPARATION
- Rate of preparation of diet (frequency):No data available
- Mixing appropriate amounts with (Type of food )
- Storage temperature of food: No data available
VEHICLE
- Justification for use and choice of vehicle (if other than water): Test chemical was mixed with 0.5% aqueous methyl cellulose
- Concentration in vehicle: 0, 20, 80 or 200 mg/kg bw/day
- Amount of vehicle (if gavage): 10ml/kg

- Lot/batch no. (if required): No data available
- Purity: No data available
Other :
One-half of the dose was given to the animals in the morning and the second half 6-8 h later

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No Data Available

Details on mating procedure:

- Impregnation procedure: [artificial insemination / purchased timed pregnant / cohoused]
- If cohoused: No Data Available
- M/F ratio per cage: 1:1
- Length of cohabitation: No Data Available
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: [no / yes (explain)]
- Verification of same strain and source of both sexes: [yes / no (explain)]
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy:The occurrence of copulation was determined by daily inspection for a copulatory plug. The day at which evidence of mating was detected was designated gestation day 0,
- Any other deviations from standard protocol: No Data Available

Duration of treatment / exposure:

Gestation day 15 to 21.

Frequency of treatment:

Twice daily. One half of the dose was given in the morning and the second half 6-8 hours later.

Remarks:

0, 20, 80 or 200 mg/kg bw/day

No. of animals per sex per dose:

Total: 86 animals

0 mg/kg bw/day: 25 animals
20 mg/kg bw/day: 25 animals
80 mg/kg bw/day:25 animals
200 mg/kg bw/day: 16 animals

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose were determined in pilot study using an identical protocol which yielded an effect level of 200 mg/ kg/day and a NOEL of less than 100 mg/kg/day for oral exposure to the test chemical.

- Rationale for animal assignment (if not random):

- Other:

Maternal examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
Time schedule: The animals were observed twice daily throughout the study for mortality and signs of overt toxicity.

BODY WEIGHT: Yes
Time schedule for examinations: Individual body weights were recorded on gestation days 0, 6, 15, 16, 17, 18, 19, 20 and 21.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No
Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
Time schedule for examinations:

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: No data
- Number of implantations: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data
- Other: No Data

Fetal examinations:

Litters were examined for numbers of live and stillborn pups and gross abnormalities. The pups were sexed and weighed individually on lactation day 0.

Statistics:

All measured parameters were subjected to Bartlett’s test for hlomogeneity of variance. Then all treatment groups and the vehicle-treated control
group were compared by one-way analysis of variance (ANOVA). Pairwise comparisons were made using the appropriate t-test (for equal and unequal variance) as described by Steel and Torrie using Dunnett’s multiple comparison tables, or pairwise comparisons were made with a Bonferroni correction to determine the significance.

Indices:

No data available

Historical control data:

No data available

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical signs of maternal physical distress during parturition included labored breathing, decreased activity, and blood staining in the abdominal, nasal, and oral areas. No evidence of increased maternal distress was noted in animals from either the mid-dose (80 mg/kg/day) or low-dose (20 mg/kg/day).

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

The incidence of maternal perinatal death was significantly increased at 200 mg/kg compared to the control group. That is, 4 of 10 animals at 200 mg/kg died or had to be sacrificed due to extreme distress whilst only 1 of 21 animals treated at 0 mg/kg died perinatally. At 20 or 80 mg/kg/day, no evidence of increased peripatum mortality was noted.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No effects on gestational body weight gain .

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 specified

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):

Treatment at 200 mg/kg resulted in a significant increase in labor duration compared to control data (mean, ≈3.5 hours at 200 mg/kg vs. mean, ≈1.2 hours at 0 mg/kg). Gestation length was unaffected by treatment.

Number of abortions:

no effects observed

Pre- and post-implantation loss:

not examined

Total litter losses by resorption:

not examined

Early or late resorptions:

not examined

Dead fetuses:

effects observed, non-treatment-related

Description (incidence and severity):

A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg).

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

Gestation length was unaffected by treatment.

Changes in number of pregnant:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

>= 80 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

dead fetuses

effects on pregnancy duration

mortality

other: labor duration

Remarks on result:

other: No toxic effects observed

Key result

Dose descriptor:

LOAEL

Effect level:

<= 200 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

mortality

other: labor duration

Remarks on result:

other: effects observed

Fetal body weight changes:

no effects observed

Reduction in number of live offspring:

effects observed, non-treatment-related

Description (incidence and severity):

A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg).

Changes in sex ratio:

no effects observed

Description (incidence and severity):

Sex ratio was unaffected by treatment.

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

No significant effects were observed on mean pups per litter or mean pup weight.

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Description (incidence and severity):

No external visible abnormalities were observed in any of the pups that survived delivery. Gross examination was not performed on fetuses that died peripartum.

Skeletal malformations:

not examined

Visceral malformations:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

>= 200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

reduction in number of live offspring

changes in sex ratio

fetal/pup body weight changes

changes in litter size and weights

external malformations

Remarks on result:

other: No toxic effects observed

Key result

Developmental effects observed:

no

Treatment related:

no

Conclusions:

NOAEL for developmental toxicity was considered at 200 mg/kg bw/day in pregnant female rats follwoing exposure to the test chemical from gestation day 15 to 21.

Executive summary:

Pregnant female rats were treated with the test chemical by oral gavageat 0, 20, 80 and 200 mg/kg bw/day from day 15 to 21 of gestation. Twenty-five rats were used per dose level up to 80 mg/kg whereas sixteen rats were used at 200 mg/kg. No significant effects were observed on gestational body weight gain and no signs of toxicity were observed until onset of delivery. Treatment at 200 mg/kg resulted in a significant increase in labor duration compared to control data (mean, ≈3.5 hours at 200 mg/kg vs. mean, ≈1.2 hours at 0 mg/kg). Gestation length was unaffected by treatment. A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg). No significant effects were observed on mean pups per litter, live pups per litter, mean pup weight, or sex ratio. No external visible abnormalities were observed in any of the pups that survived delivery. Gross examination was not performed on fetuses that died peripartum. The incidence of maternal perinatal death was significantly increased at 200 mg/kg compared to the control group. That is, 4 of 10 animals at 200 mg/kg died or had to be sacrificed due to extreme distress whilst only 1 of 21 animals treated at 0 mg/kg died perinatally. NOAEL for developmental toxicity was considered at 200 mg/kg bw/day in pregnant female rats follwoing exposure to the test chemical from gestation day 15 to 21.

Reference 2

Endpoint:

developmental toxicity

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

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:

read-across source

Principles of method if other than guideline:

Pregnant rabbits were exposed to the test chemical from gestation day 7-19 in order to study potential adverse effects on development and teratology.

GLP compliance:

not specified

Limit test:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Timed pregnant female New Zealand White rabbits were acquired for the study. They were 5 to 6.5 months of age and weighted 2.8 to 4.3 kg on gestation day 8. They were housed in stainless stel cages. Room lighting was set for a 12 hour light/dark cycle. The animals were fed 100 g of Purina Regular Rabbit Chow (Ralston, VA, USA) one day after arrival. Thereafter, the animals were fed 150 g of the same feed every day. Water was available ad libitum.

Route of administration:

oral: gavage

Vehicle:

not specified

Details on exposure:

The test chemical as a suspension in 0.5% methylcellulose was given by oral gavage at a dose volume of 3 ml/kg. Control animals received 0.5% methylcellulose by oral gavage by the same dose regimen.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No details.

Details on mating procedure:

Timed pregnant female New Zealand White rabbits were acquired for the study.

Duration of treatment / exposure:

Gestation day 7 to 19.

Frequency of treatment:

Daily

Duration of test:

Gestation day 7-29.

Remarks:

0 (vehicle control), 125, 250 and 350 mg/kg bw/day

No. of animals per sex per dose:

20

Control animals:

yes, concurrent vehicle

Maternal examinations:

Mortality, morbidity, body weights and food intake. Body weights and food intake were recorded on the day of arrival and then daily from gestation day 8.

Ovaries and uterine content:

The numbers of corpora lutea per ovary were recorded. In addition, the number, type, and location of implantation sites were determined.

Fetal examinations:

Number of viable fetuses, sex ratio, fetal weight and gross, visceral and skeletal anomalies/malformtation.

Statistics:

Data on body ewight, food intake and cesarean section observations were subjected to Welch trend test. Data on fetal body weights were subjected to linear trend after adjustment for litter size. Data on sex ratio were subjected to analysis of covariance. Data on gross, visceral and skeletal observations were subjected to an exact test for trend in proportions.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical signs of toxicity were observed at ≥250 mg/kg and included loose stool and short periods of decreased activity which resolved within 1 hour after dose administration

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Mortality was observed in animals treated at 250 (1 of 20) and 350 mg/kg (3 of 20) between gestation day 14 and 16.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Body weight gain was significantly depressed at ≥250 mg/kg from gestation day 7 to 13 compared to the control data. Over the entire study period (gestation day 7 to 29), body weight gains were 15% lower at 250 mg/kg and 27% lower at 350 mg/kg compared to the control data. Terminal body weight was significantly lower at 350 mg/kg (mean 3.85 kg) compared to the control data (mean, 4.10 kg).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

The decrease in body weight gain at ≥250 mg/kg was accompanied by reduced food intake.

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

Number of abortions:

effects observed, treatment-related

Description (incidence and severity):

One other pregnant rat treated at 350 mg/kg aborted on gestation day 22.

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not examined

Changes in number of pregnant:

not specified

Details on maternal toxic effects:

No treatment-related effects were observed on corpora lutea, implantation sites, pre-implantation losses, embryo mortality, or fetal mortality.

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat. (dissolved fraction)

Basis for effect level:

body weight and weight gain

clinical signs

dead fetuses

early or late resorptions

food consumption and compound intake

mortality

number of abortions

pre and post implantation loss

total litter losses by resorption

Dose descriptor:

LOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

mortality

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

The mean fetal weight was slightly but significantly lower at 350 mg/kg (mean 41.6 gram) compared to the control group (mean 44.1 gram).

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

The mean numbers of viable fetuses were 8.4, 7.7, 8.5 and 8.6 at 0, 1250, 250 and 350 mg/kg bw/day, respectively.

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Description (incidence and severity):

All fetuses were normal externally.

Skeletal malformations:

effects observed, non-treatment-related

Description (incidence and severity):

There were no skeletal malformation attributed to the test chemical.

Visceral malformations:

no effects observed

Description (incidence and severity):

There were no visceral malformation attributed to the test chemical.

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

changes in sex ratio

external malformations

skeletal malformations

visceral malformations

Abnormalities:

no effects observed

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

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

Treatment related:

yes

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

NOAEL for maternal systemic toxicity was established at 125 mg/kg bw/day in rabbits following exposure to the test chemical by oral gavage from gestation day 7 to 19. Reduction in mean fetal weight at 350 mg/kg bw/day was the only adverse effects on development reported. This effect was observed at a dose level that produced marked maternal toxicity as evident by increased mortality, clinical signs of toxicity, and depressed maternal body weight gain.

Executive summary:

The chemical was given by oral gavage to pregnant rabbits at 0 (vehicle control), 125, 250 and 350 mg/kg bw/day from gestation day 7 to 19. Each treatment group consisted of 20 animals. Mortality was observed in animals treated at 250 (1 of 20) and 350 mg/kg (3 of 20) between gestation day 14 and 16. One other pregnant rat treated at 350 mg/kg aborted on gestation day 22. Body weight gain was significantly depressed at ≥250 mg/kg from gestation day 7 to 13 compared to the control data. Over the entire study period (gestation day 7 to 29), body weight gains were 15% lower at 250 mg/kg and 27% lower at 350 mg/kg compared to the control data. The decrease in body weight gain was accompanied by reduced food intake. Terminal body weight was significantly lower at 350 mg/kg (mean 3.85 kg) compared to the control data (mean, 4.10 kg). Clinical signs of toxicity were observed at ≥250 mg/kg and included loose stool and short periods of decreased activity which resolved within 1 hour after dose administration. No treatment-related effects were observed on corpora lutea, implantation sites, pre-implantation losses, embryo mortality, or fetal mortality. The mean fetal weight was slightly but significantly lower at 350 mg/kg (mean 41.6 gram) compared to the control group (mean 44.1 gram). All fetuses were normal externally. There were no treatment-related visceral or skeletal anomalies reported in the study.

Reference 3

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from a peer reviewed journal.

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Pregnant rats were exposed to the test chemical during gestation to investiagte potential adverse effects on development and teratology.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Sprague-Dawley-derived (Tif:RAIf[SPF] hybrids R1I/1 XRlI/2)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: from a closed breeding colony of Ciba-Geigy.
- Age at study initiation: 60 days old
- Weight at study initiation: 200 g
- Fasting period before study: No data available

- Housing: The animals were kept in small groups of 3-5 in Macrolon® cages equipped with a wire-mesh top and water bottle. Granulated soft wood served as a bedding material. The cages were placed in movable rackshoused in solid-bottom cages with wood shavings for bedding,
- Use of restrainers for preventing ingestion (if dermal): yes/no
- Diet (e.g. ad libitum): A certified standard cube diet (Nafag No. 814, Gossau SG, Switzerland) ad libitum
- Water (e.g. ad libitum): drinking water were provided ad libitum
- Acclimation period: No data available


ENVIRONMENTAL CONDITIONS
- Temperature (°C):21 ± 2°C
- Humidity (%): 55 ± 10%.
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light):The room was illuminated for 12 h (06.00-18.00 h).

Route of administration:

oral: gavage

Vehicle:

not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: [artificial insemination / purchased timed pregnant / cohoused]
- If cohoused: Females were mated overnight with males of proven fertility in racks containing modified cages.
- M/F ratio per cage: Each cage was subdivided into two parts by a shutter, one part containing the female(s) and the other part containing the male. The sexes remained separated until about 02.00 h, when the shutter opened by means of an automatic device.
- Length of cohabitation: Overnight
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: [no / yes (explain)]
- Verification of same strain and source of both sexes: [yes / no (explain)]
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy: The females showing either a vaginal plug or spermatozoa in the vaginal smear, The day of insemination, thus confirmed, was designated ‘day 0’ of pregnancy.
- Any other deviations from standard protocol: No Data Available

Duration of treatment / exposure:

Day 6 to 15 of gestation

Frequency of treatment:

daily

Remarks:

0, 30,90,180 mg/kg bw/day

No. of animals per sex per dose:

Total: 72 animals
0 mg/kg bw/day:19
30 mg/kg bw/day:17
90 mg/kg bw/day:19
180 mg/kg bw/day:17

Control animals:

yes, concurrent vehicle

Details on study design:

Dams were sacrificed on day 21 of gestation i.e. shortly before delivery.

Maternal examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
Time schedule: No Data Available

BODY WEIGHT: Yes
Time schedule for examinations: No Data Available

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes.
Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data
Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No data


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
Time schedule for examinations: No Data Available

OTHER: No Data Available

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: No data
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other:

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes
- Skeletal examinations: Yes
- Head examinations: No data

Statistics:

Chi-squared test and t-test (one-tailed).

Historical control data:

Not specified

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Dams treated at 180 mg/kg reacted to treatment by some reduction in food intake.

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:

effects observed, non-treatment-related

Description (incidence and severity):

1 of 17 pregnant rats treated at 180 mg/kg bw/day aborted.

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

effects observed, treatment-related

Description (incidence and severity):

Embryofetal lethality was markedly increased at 180 mg/kg (mean, 29.0% lethality) compared to control data (mean, 4.6% lethality).

Changes in pregnancy duration:

not examined

Changes in number of pregnant:

no effects observed

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

>= 90 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

dead fetuses

food consumption and compound intake

number of abortions

pre and post implantation loss

Key result

Dose descriptor:

LOAEL

Effect level:

<= 180 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

dead fetuses

food consumption and compound intake

Abnormalities:

not specified

Localisation:

not specified

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

The mean body weights of live fetuses were significantly lower at ≥90 mg/kg compared to control data.

Reduction in number of live offspring:

effects observed, treatment-related

Description (incidence and severity):

Embryofetal lethality was markedly increased at 180 mg/kg (mean, 29.0% lethality) compared to control data (mean, 4.6% lethality).

Changes in sex ratio:

not examined

Changes in litter size and weights:

not examined

Changes in postnatal survival:

not examined

External malformations:

not specified

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

Treatment at ≥90 mg/kg resulted retarded skeletal maturation as evident by significantly higher incidences of the following features: absent ossification in phalangeal nuclei (at 90 and 180 mg/kg), incomplete ossification of 5th sternebra (at 180 mg/kg), dumbbell-shaped centers of thoracic vertebrae (at 90 and 180 mg/kg), and abnormal ossification of thoracic vertebrae (at 90 and 180 mg/kg).

Visceral malformations:

effects observed, non-treatment-related

Description (incidence and severity):

Teratogenicity was marginal at 80 mg/kg (0.7% of fetuses abnormal) and marked at 180 mg/kg (≈30% of fetuses abnormal). Types of malformations at 180 mg/kg included generalized edema, brachymelia, cranio(rachi)schisis, meningo-encephalocele, hydrocephaly, spina bifida aperta, various malformation of the CNS, cleft palate and lip, costal fusion(s), and synostoses of sternebrae.

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

>= 30 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

skeletal malformations

visceral malformations

Key result

Dose descriptor:

LOAEL

Effect level:

<= 90 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

fetal/pup body weight changes

skeletal malformations

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

other: Numerous skeletal and visceral abnormalities at 90 and 180 mg/kg bw/day

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

90 mg/kg bw/day (nominal)

Treatment related:

yes

Relation to maternal toxicity:

developmental effects in the absence of maternal toxicity effects

Dose response relationship:

yes

Test Chemical: embryotoxity and teratogenicity following maternal oral treatment on days 6-15 of pregnancy   Dosage mg/kg Number of female with implantation Mean of implantation site per female Number of female with abortion Embryo and fetolethality, mean % per dam Number of live foetuses Mean body weight of live foetuses (g)   Males Females 0 19 14.8 0/19 4.6 127 141 5.41 0.42 30 17 15.4 1/17 5.0 121 128 5.42 0.45 90 19 16.1 1/19 4.9 154 136 5.25 0.41** 180 17 15.1 1/17 29.0* 93 88 3.86 0.67**    *X2test, P < 0.01. ** t test, one-tailed, p < 0.01.     Test Chemical: delay of skeletal maturation as stated for the near-term foetuses   0 30mg/kg 90 mg/kg 180mg/kg   Number of skeletons examined 180 165 192 123 Ossification still absent in phalangeal nuclei, %     Fore-limb 5.6 7.9 26.0^a 93.5^a   Hind-limb 43.9 41.2 77.6^a 100^a   5th stemebra still incompletely ossified. % 6.7 8.5 5.7 78.9^a   Some centres of thoracic vertebrae dumbbell-shaped, % 1.1 1.2 10.9^a 45.5^a   Some thoracic vertebrae with 2 small ossified centres, % 0 0 4.7^a 83.7^a   Outside 99% confidence limits of control incidences       Test Chemical: Types and incidences of malformations at 180 mg/kg   Type of malformation   Number of litters affected (n = 17)   Number of fetuses affected       total %     Generalized oedema (hydrops) 2 2/181 1.1     Brachymelia (right fore-limb) 1 1/181 0.55     Cranio(rachi)schisis 14 41/181^a 22.7     Meningo-encephalocele 1 1/181 0.55     Hydrocephaly 1 2/181 1.1     Spina bifida aperta 2 3/181 1.7   CNS total 15 47/181 26.0       Cleft palate and lip (cheilopalatoschisis) 2 2/181 1.1     Costal fusion(s) 10 12/123 9.8       Synostoses of stemebrac 4 8/123 6.5     A3 additionally with ‘open eyes’.

Conclusions:

NOAEL for developmental toxicity and teratogenicity was esbalished at 30 mg/kg bw/day in pregnant female rats following exposure to the test chemical from day 6 to 15 of gestation. Doses up to 180 mg/kg bw/day from day 6 to 15 of gestation were well-tolerated in the pregnant animals.

Executive summary:

Pregnant female rats were exposed to the test chemical by oral gavage at 0, 30, 90 and 180 mg/kg bw/day from day 6 to 15 of gestation. The number of dams treated were 19, 17, 19 and 17 at 0, 30, 90 and 180 mg/kg, respectively. Dams were sacrificed on day 21 of gestation i.e. shortly before delivery. Dams treated at 180 mg/kg reacted to treatment by some reduction in food intake. Embryofetal lethality was markedly increased at 180 mg/kg (mean, 29.0% lethality) compared to control data (mean, 4.6% lethality). The mean body weights of live fetuses were significantly lower at ≥90 mg/kg compared to control data. Treatment at ≥90 mg/kg resulted retarded skeletal maturation as evident by significantly higher incidences of the following features: absent ossification in phalangeal nuclei (at 90 and 180 mg/kg), incomplete ossification of 5^thsternebra (at 180 mg/kg), dumbbell-shaped centers of thoracic vertebrae (at 90 and 180 mg/kg), and abnormal ossification of thoracic vertebrae (at 90 and 180 mg/kg). Teratogenicity was marginal at 90 mg/kg (0.7% of fetuses abnormal) and marked at 180 mg/kg (≈30% of fetuses abnormal). Types of malformations at 180 mg/kg included generalized edema, brachymelia, cranio(rachi)schisis, meningo-encephalocele, hydrocephaly, spina bifida aperta, various malformation of the CNS, cleft palate and lip, costal fusion(s), and synostoses of sternebrae. NOAEL for developmental toxicity and teratogenicity was esbalished at 30 mg/kg bw/day in pregnant female rats following exposure to the test chemical from day 6 to 15 of gestation. Doses up to 180 mg/kg bw/day from day 6 to 15 of gestation were well-tolerated in the pregnant animals.

Reference 4

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data from peer reviewed journal

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Pregnant rats were exposed to the test chemical during gestation to investiagte potential adverse effects on development and teratology.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: albino rats bred (COBS)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., North Wilmington, Massachusetts
- Age at study initiation: 100 days when purchased
- Weight at study initiation: No data
- Fasting period before study: No data
- Housing: No data
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: No data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data
- Humidity (%):No data
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): No data

IN-LIFE DATES: From: To: No data

Route of administration:

oral: gavage

Vehicle:

other: 1.5% aqueous methyl cellulose

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test chemical was dissolved with 1.5% aqueous methyl cellulose at dose level of 0 or 200 mg/kg bw/day.

DIET PREPARATION
- Rate of preparation of diet (frequency): No data
- Mixing appropriate amounts with (Type of food): No data
- Storage temperature of food: No data

VEHICLE
- Justification for use and choice of vehicle (if other than water): 1.5% aqueous methyl cellulose
- Concentration in vehicle: 0 or 200 mg/kg bw/day
- Amount of vehicle (if gavage): No data
- Lot/batch no. (if required): No data
- Purity: No data

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No Data Available

Details on mating procedure:

No data available

Duration of treatment / exposure:

Day 6 to 15 of gestation

Frequency of treatment:

Daily

Remarks:

0 and 200 mg/kg bw/day

No. of animals per sex per dose:

Total: 96 animals
Control I :17
Control I :16
Control I :21

200mg/kg bw/day:21
200mg/kg bw/day:21

Control animals:

yes, concurrent vehicle

Details on study design:

3 vehicle control groups (treated at 0 mg/kg bw/day) and 2 grops (treated at 200 mg/kg bw/day) were used in the study.

Maternal examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: yes

DETAILED CLINICAL OBSERVATIONS: Yes
Time schedule: No Data Available

BODY WEIGHT: Yes
Time schedule for examinations: No Data Available

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No
Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
Time schedule for examinations: No Data Available

Ovaries and uterine content:

The ovaries and uterine content was examined after termination:
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: No Data Available

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes (Internal development was evaluated in 1/3 of the fetuses by the freehand razor blade sectioning technique)
- Skeletal examinations: Yes (Two-thirds of all fetuses of each sex from each litter were examined for skeletal development using the alizarin staining metho).
- Head examinations: No data available

Statistics:

Fetal viability data were subjected to 2 types of statistical analysis. First, in a chi-square analysis, the number of resorption sites per implantation site of each test animal was compared to the expected incidence. The expected incidence was calculated from data obtained from the 3 untreated control groups. The second analysis utilized the ranking method of Weil (1970). For this analysis the individual viability indices of each test group were ranked with individual viability indices of each control group.

Historical control data:

Not specified

Clinical signs:

no effects observed

Description (incidence and severity):

No untoward reactions were observed during the study.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No significant effects were observed on mean maternal body weight gain from day 0 to 20 of gestation (mean gain, 146 gram at 0 mg/kg vs. mean gain, 134 gram at 200 mg/kg).

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

Number of abortions:

not specified

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

The mean numbers of implantation sites at 0 and 200 mg/kg bw/day were unaffected by treatment.

Total litter losses by resorption:

effects observed, treatment-related

Description (incidence and severity):

One of the groups treated at 200 mg/kg showed a significant increase in the number of resorptions compared to control data.

Early or late resorptions:

not specified

Dead fetuses:

effects observed, treatment-related

Description (incidence and severity):

One of the groups treated at 200 mg/kg showed a significant decrease in the number of viable fetuses when compared to the control data.

Changes in pregnancy duration:

not examined

Key result

Dose descriptor:

LOAEL

Effect level:

<= 200 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

dead fetuses

total litter losses by resorption

Fetal body weight changes:

not specified

Reduction in number of live offspring:

effects observed, treatment-related

Description (incidence and severity):

One of the groups treated at 200 mg/kg showed a significant decrease in the number of viable fetuses when compared to the control data.

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

effects observed, treatment-related

Description (incidence and severity):

A significant increase in the number of fetuses with external abnormalities was observed in one of the two groups treated at 200 mg/kg compared to control data. The abnormalities included runts, craniorachischisis, gastroschisis, spiraled caudia and talipes.

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

The incidences of skeletal abnormalities were markedly increased in both groups treated at 200 mg/kg compared to control data.

Visceral malformations:

effects observed, treatment-related

Description (incidence and severity):

Tthe incidence of visceral abnormalities was significantly increased in one of the two groups treated at 200 mg/kg compared to control data

Details on embryotoxic / teratogenic effects:

The aggregated incidences of external, skeletal and visceral abnormalities at 200 mg/kg were 1.4, 71.4 and 29.6%, respectively. At 0 mg/kg, the aggregated incidences of external, skeletal and visceral abnormalities were 0.4, 0.8 and 12.6%, respectively. The incidences of skeletal abnormalities did not include deficient ossification of sternum sections because that was common to all groups. No details were given on what types of skeletal abnormalities that occurred at 200 mg/kg.

Key result

Dose descriptor:

LOAEL

Effect level:

<= 200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

reduction in number of live offspring

external malformations

skeletal malformations

visceral malformations

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

other: Gross, skeletal and visceral abnormalities.

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

200 mg/kg bw/day (nominal)

Treatment related:

yes

Relation to maternal toxicity:

developmental effects in the absence of maternal toxicity effects

Dose response relationship:

no

Relevant for humans:

yes

Table 1: Reproductive Effects of the test chemical in albino rats

Group	Pregnant females examined	Autopsy findings				Females with one or more resorption sites
		Corpora lutea	Implant-ation sites	Resorp-tion sites	Viable fetuses	Total	Percent
Control I	17	12.9	10.9	0.6	10.3	8	47.1
Control II	16	12.6	10.6	0.9	9.7	10	62.5
Control III	21	12.9	10.9	0.4	10.4	9	42.8
I^a	21	12.5	10.6	0.5	10.1	6	28.6
II^a	21	12.2	10.0	2.3b	7.7b	15b	71.4b

a - Test chemical, 200 mg/kg/day; b- Statistically different from controls, p < 0.05

 

Table 2: Effects of the test chemical on Fetal Development in rats

Group	Fetuses with external abnormalities		Fetuses with skeletal abnormalities		Fetuses with internal abnormalities
	Number	Percent	Number	Percent	Number	Percent
Control I	0/175	0.0	0/116	0.0	10/59	17.0
Control II	0/156	0.0	2/104	1.9	6/52	11.5
Control III	2/218	0.9	1/146	0.7	7/72	9.7
I^a	4/212	1.9	95/140^b	67.8^b	13/72	18.1
II^a	10/161^b	6.2^b	82/108^b	75.9^b	24/53^b	45.3^b

 a - Test chemicals, 200 mg/kg/day; b- Statistically different from controls, p < 0.01

 

Conclusions:

LOAEL for developmental toxicity and teratogenicity was established at 200 mg/kg bw/day in pregnant female rats following exposure to the test chemical from day 6 of 15 of gestation. There were no signs of maternal systemic toxicity in the study.

Executive summary:

Pregnant female rats were exposed to the test chemical at at 0 and 200 mg/kg bw/day from day 6 to 15 of gestation. Forty-one animals divided into two separate groups were exposed to sodium salicylate at 200 mg/kg. The control data consisted of 54 rats divided into three groups. The animals were sacrificed at day 20 of gestation. No significant effects were observed on mean maternal body weight gain from day 0 to 20 of gestation (mean gain, 146 gram at 0 mg/kg vs. mean gain, 134 gram at 200 mg/kg). No maternal deaths occurred and there were no untoward reactions to treatment. One of the groups treated at 200 mg/kg showed a significant increase in the number of resorptions and a significant decrease in the number of viable fetuses when compared to the control data. A significant increase in the number of fetuses with external abnormalities was observed in one of the two groups treated at 200 mg/kg compared to control data. The incidences of skeletal abnormalities were markedly increased in both groups treated at 200 mg/kg compared to control data. Lastly, the incidence of visceral abnormalities was significantly increased in one of the two groups treated at 200 mg/kg compared to control data. The aggregated incidences of external, skeletal and visceral abnormalities at 200 mg/kg were 1.4, 71.4 and 29.6%, respectively. At 0 mg/kg, the aggregated incidences of external, skeletal and visceral abnormalities were 0.4, 0.8 and 12.6%, respectively. The incidences of skeletal abnormalities did not include deficient ossification of sternum sections because that was common to all groups. No details were given on what types of skeletal abnormalities that occurred at 200 mg/kg.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

200 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The data is K2 level as the data has been obtained from an experimental study from the reliable journal

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Developmental Toxicity

Data available from different studies were reviewed to determine the developmental toxicity of test chemical. The studies are as mentioned below:

 

Study 1

Pregnant female rats were treated with the test chemical by oral gavageat 0, 20, 80 and 200 mg/kg bw/day from day 15 to 21 of gestation. Twenty-five rats were used per dose level up to 80 mg/kg whereas sixteen rats were used at 200 mg/kg. No significant effects were observed on gestational body weight gain and no signs of toxicity were observed until onset of delivery. Treatment at 200 mg/kg resulted in a significant increase in labor duration compared to control data (mean, ≈3.5 hours at 200 mg/kg vs. mean, ≈1.2 hours at 0 mg/kg). Gestation length was unaffected by treatment. A non-statistical increase in fetal peripartum deaths was reported at 200 mg/kg compared to the control group (9.7% fetuses affected at 200 mg/kg vs 3.1% of fetuses affected at 0 mg/kg). No significant effects were observed on mean pups per litter, live pups per litter, mean pup weight, or sex ratio. No external visible abnormalities were observed in any of the pups that survived delivery. Gross examination was not performed on fetuses that died peripartum. The incidence of maternal perinatal death was significantly increased at 200 mg/kg compared to the control group. That is, 4 of 10 animals at 200 mg/kg died or had to be sacrificed due to extreme distress whilst only 1 of 21 animals treated at 0 mg/kg died perinatally. NOAEL for developmental toxicity was considered at 200 mg/kg bw/day in pregnant female rats follwoing exposure to the test chemical from gestation day 15 to 21.

Study 2

The chemical was given by oral gavage to pregnant rabbits at 0 (vehicle control), 125, 250 and 350 mg/kg bw/day from gestation day 7 to 19. Each treatment group consisted of 20 animals. Mortality was observed in animals treated at 250 (1 of 20) and 350 mg/kg (3 of 20) between gestation day 14 and 16. One other pregnant rat treated at 350 mg/kg aborted on gestation day 22. Body weight gain was significantly depressed at ≥250 mg/kg from gestation day 7 to 13 compared to the control data. Over the entire study period (gestation day 7 to 29), body weight gains were 15% lower at 250 mg/kg and 27% lower at 350 mg/kg compared to the control data. The decrease in body weight gain was accompanied by reduced food intake. Terminal body weight was significantly lower at 350 mg/kg (mean 3.85 kg) compared to the control data (mean, 4.10 kg). Clinical signs of toxicity were observed at ≥250 mg/kg and included loose stool and short periods of decreased activity which resolved within 1 hour after dose administration. No treatment-related effects were observed on corpora lutea, implantation sites, pre-implantation losses, embryo mortality, or fetal mortality. The mean fetal weight was slightly but significantly lower at 350 mg/kg (mean 41.6 gram) compared to the control group (mean 44.1 gram). All fetuses were normal externally. There were no treatment-related visceral or skeletal anomalies reported in the study.

Study 3

Pregnant female rats were exposed to the test chemical by oral gavage at 0, 30, 90 and 180 mg/kg bw/day from day 6 to 15 of gestation. The number of dams treated were 19, 17, 19 and 17 at 0, 30, 90 and 180 mg/kg, respectively. Dams were sacrificed on day 21 of gestation i.e. shortly before delivery. Dams treated at 180 mg/kg reacted to treatment by some reduction in food intake. Embryofetal lethality was markedly increased at 180 mg/kg (mean, 29.0% lethality) compared to control data (mean, 4.6% lethality). The mean body weights of live fetuses were significantly lower at ≥90 mg/kg compared to control data. Treatment at ≥90 mg/kg resulted retarded skeletal maturation as evident by significantly higher incidences of the following features: absent ossification in phalangeal nuclei (at 90 and 180 mg/kg), incomplete ossification of 5thsternebra (at 180 mg/kg), dumbbell-shaped centers of thoracic vertebrae (at 90 and 180 mg/kg), and abnormal ossification of thoracic vertebrae (at 90 and 180 mg/kg). Teratogenicity was marginal at 90 mg/kg (0.7% of fetuses abnormal) and marked at 180 mg/kg (≈30% of fetuses abnormal). Types of malformations at 180 mg/kg included generalized edema, brachymelia, cranio(rachi)schisis, meningo-encephalocele, hydrocephaly, spina bifida aperta, various malformation of the CNS, cleft palate and lip, costal fusion(s), and synostoses of sternebrae. NOAEL for developmental toxicity and teratogenicity was esbalished at 30 mg/kg bw/day in pregnant female rats following exposure to the test chemical from day 6 to 15 of gestation. Doses up to 180 mg/kg bw/day from day 6 to 15 of gestation were well-tolerated in the pregnant animals.

Study 4

Pregnant female rats were exposed to the test chemical at at 0 and 200 mg/kg bw/day from day 6 to 15 of gestation. Forty-one animals divided into two separate groups were exposed to sodium salicylate at 200 mg/kg. The control data consisted of 54 rats divided into three groups. The animals were sacrificed at day 20 of gestation. No significant effects were observed on mean maternal body weight gain from day 0 to 20 of gestation (mean gain, 146 gram at 0 mg/kg vs. mean gain, 134 gram at 200 mg/kg). No maternal deaths occurred and there were no untoward reactions to treatment. One of the groups treated at 200 mg/kg showed a significant increase in the number of resorptions and a significant decrease in the number of viable fetuses when compared to the control data. A significant increase in the number of fetuses with external abnormalities was observed in one of the two groups treated at 200 mg/kg compared to control data. The incidences of skeletal abnormalities were markedly increased in both groups treated at 200 mg/kg compared to control data. Lastly, the incidence of visceral abnormalities was significantly increased in one of the two groups treated at 200 mg/kg compared to control data. The aggregated incidences of external, skeletal and visceral abnormalities at 200 mg/kg were 1.4, 71.4 and 29.6%, respectively. At 0 mg/kg, the aggregated incidences of external, skeletal and visceral abnormalities were 0.4, 0.8 and 12.6%, respectively. The incidences of skeletal abnormalities did not include deficient ossification of sternum sections because that was common to all groups. No details were given on what types of skeletal abnormalities that occurred at 200 mg/kg.

Toxicity to reproduction: other studies

Description of key information

Toxicity to reproduction

Human data available from different studies were reviewed to determine the reproductive toxicity of test chemical. The studies are as mentioned below:

Study 1

The effect of the test chemical on human gestation was investigated in this retrospective study. The study included three groups. Group 1 consisted of 103 patients, each with therapeutic intake of greater than 3250 mg/day of the test chemical, for at least the last 6 months of gestation. These patients had rheumatoid arthritis, non-specific collagen disease, or degenerative musculoskeletal disease. Group 2 included 52 patients with rheumatoid arthritis, non-specific collagen disease, or degenerative musculoskeletal disease during gestation who were no taking therapeutic doses of the test chemical. Group 3 consisted of 50 patients without known disease who were test chemical-free during gestation. The data revealed a significant increase in gestation length in Group 1 (mean, 286.1 days) as compared to Group 2 (mean 275.2 days) and Group 3 (mean, 278.6 days). Moreover, the authors noted a significant increase in the frequency of postmaturity (gestations over 42 weeks) in Group 1 compared to Group 3. Labor duration was also significantly increased in Group 1 (mean, 12.1 hours) compared to Group 2 (mean, 7.3 hours) and Group 3 (mean, 6.96 hours). The observed effects on gestation length and labor duration were attributed to the capacity of the test chemical to inhibit prostaglandin synthesis. Data from the study also revealed a significant increase in estimated blood loss during delivery in Group 1 compared to the other two groups. This outcome was attributed to the capacity of the test chemical to affect platelets and clotting activity. Treatment with the test chemical was found to have no significant effect on birth weight (mean, 3077 gram in Group 1 vs. mean, 2972 gram in Group 2). Mean birth weight in Group 3 was however significantly higher (mean, 3379 gram) compared to Group 1 and 2. This effect was attributed to the healthier state of the women in Group 3 who did not suffer from serious systemic diseases.

Study 2

The effect of the test chemical on human pregnancy was investigated. The study included three groups. Group 1 consisted of 63 patients with a daily intake of the test chemical during pregnancy by powder. Group 2 consisted of 81 patients with an intake of the test chemical at least once a week during pregnancy either by the same powders as Group 1 or by tablets. None of the patients in Group 1 or 2 took the test chemical for chronic disease, however, they were all habitual users. Group 3 consisted of 63 test chemical-free patients that were matched to Group 1 for age, parity, gravidity, ethnic group, and social class. The incidence of smoking was however significantly higher in Group 1 as compared to Group 3. The incidence of anemia was also significantly higher in Group 1 as compared to Group 3. Mean gestation length was significantly longer in Group 1 (mean, 39.7 weeks) and Group 2 (mean 39.8 weeks) as compared to Group 3 (mean 38.7 weeks). No significant effects were observed on the number of pregnancies lasting longer than 42 weeks or on the number of premature labors. Labor duration tended to be greater in Group 1 (mean, 5.6 hr) and 2 (mean, 5.5 hr) compared to Group 3 (mean 4.8 hr). Mean birthweight (corrected for: gestation length, being first-born and smoking) was significantly lower in Group 1 babies (mean, 3283 gram) as compared to Group 3 babies (mean, 3502 gram). In Group 1 and 2, corrected birthweights were inversely associated with duration of test chemical intake. This indicates that the difference in corrected birthweight between Group 1 and 3 could be due to cumulative secondary effect from maternal factor(s). The incidences of major congenital anomalies were 3, 5 and 2% in Group 1, 2 and 3, respectively. The incidence of stillbirth was significantly increase in Group 1 (5.8%) as compared to Group 3 (1.2%). No significant effect was observed on neonatal mortality; however, the incidence of perinatal death was significantly increased in Group 1 (8.7%) as compared to Group 3 (2.7%). The above data on fetal wastage needs to be interpreted with caution as the authors included data from present and past pregnancies, which is somewhat questionable because the probability of stillbirth and perinatal death may not be independent from pregnancy to pregnancy. The influence of smoke and of other constituents of the powders to the results was not investigated.

Link to relevant study records

Reference

Reference 1

Endpoint:

toxicity to reproduction: other studies

Type of information:

other: Retrospective study in humans

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

The effects of the test chemical in human gestation were investigated retrospectively.

Species:

other: humans

Sex:

female

Route of administration:

oral: capsule

Details on exposure:

The group of patients exposed to the test chemical had a therapeutic intake of the test chemical of greater than 3250 mg/day for at least the last 6 months of gestation.

Duration of treatment / exposure:

The group of patients exposed to the test chemical had a therapeutic intake of the test chemical of greater than 3250 mg/day for at least the last 6 months of gestation.

Frequency of treatment:

Daily

Duration of test:

Not specified.

Remarks:

0 (Group 3), 0 (Group 2) and >3250 mg/day (Group 1)

No. of animals per sex per dose:

Group 1: 103 patients
Group 2: 52 patients
Group 3: 50 patients

Details on study design:

The study included three groups. Group 1 consisted of 103 patients, each with therapeutic intake of greater than 3250 mg/day of the test chemical, for at least the last 6 months of gestation. These patients had rheumatoid arthritis, non-specific collagen disease, or degenerative musculoskeletal disease. Group 2 included 52 patients with rheumatoid arthritis, non-specific collagen disease, or degenerative musculoskeletal disease during gestation who were no taking therapeutic doses of the test chemical. Group 3 consisted of 50 patients without known disease who were test chemical-free during gestation.

Statistics:

All data were obtained directly from patient records and were analysed statistically using the t or Chi-square tests. A P value of <0.05 was considered significant.

Key result

Dose descriptor:

LOAEL

Effect level:

<= 3 250 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Increased gestation lenght, increased frequency of postmaturity, increased labor duration, increased blood loss during delivery

The data revealed a significant increase in gestation length in Group 1 (mean, 286.1 days) as compared to Group 2 (mean 275.2 days) and Group 3 (mean, 278.6 days). Moreover, the authors noted a significant increase in the frequency of postmaturity (gestations over 42 weeks) in Group 1 compared to Group 3. Labor duration was also significantly increased in Group 1 (mean, 12.1 hours) compared to Group 2 (mean, 7.3 hours) and Group 3 (mean, 6.96 hours). Data from the study also revealed a significant increase in estimated blood loss during delivery in Group 1 compared to the other two groups. Treatment with the test chemical was found to have no significant effect on birth weight (mean, 3077 gram in Group 1 vs. mean, 2972 gram in Group 2). Mean birth weight in Group 3 was however significantly higher (mean, 3379 gram) compared to Group 1 and 2.

Conclusions:

Exposure to the test chemical during human gestation was associated with increased gestation length, increased frequency of postmaturity, increased labor duration, and increased estimated blood loss during delivery. The findings need to be interpreted with caution as the effects were observed in seriously diseased patients with chronic intake of acetylsalicylic acid for therapeutic reasons.

Executive summary:

The effect of the test chemical on human gestation was investigated in this retrospective study. The study included three groups. Group 1 consisted of 103 patients, each with therapeutic intake of greater than 3250 mg/day of the test chemical, for at least the last 6 months of gestation. These patients had rheumatoid arthritis, non-specific collagen disease, or degenerative musculoskeletal disease. Group 2 included 52 patients with rheumatoid arthritis, non-specific collagen disease, or degenerative musculoskeletal disease during gestation who were no taking therapeutic doses of the test chemical. Group 3 consisted of 50 patients without known disease who were test chemical-free during gestation. The data revealed a significant increase in gestation length in Group 1 (mean, 286.1 days) as compared to Group 2 (mean 275.2 days) and Group 3 (mean, 278.6 days). Moreover, the authors noted a significant increase in the frequency of postmaturity (gestations over 42 weeks) in Group 1 compared to Group 3. Labor duration was also significantly increased in Group 1 (mean, 12.1 hours) compared to Group 2 (mean, 7.3 hours) and Group 3 (mean, 6.96 hours). The observed effects on gestation length and labor duration were attributed to the capacity of the test chemical to inhibit prostaglandin synthesis. Data from the study also revealed a significant increase in estimated blood loss during delivery in Group 1 compared to the other two groups. This outcome was attributed to the capacity of the test chemical to affect platelets and clotting activity. Treatment with the test chemical was found to have no significant effect on birth weight (mean, 3077 gram in Group 1 vs. mean, 2972 gram in Group 2). Mean birth weight in Group 3 was however significantly higher (mean, 3379 gram) compared to Group 1 and 2. This effect was attributed to the healthier state of the women in Group 3 who did not suffer from serious systemic diseases.

Reference 2

Endpoint:

toxicity to reproduction: other studies

Type of information:

other: Human study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

The effects of the test chemical on human gestation was investigated.

Species:

other: Humans

Sex:

female

Route of administration:

oral: unspecified

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

Not specified.

Frequency of treatment:

Group 1: Daily intake of the test chemical during pregnancy
Group 2: Intake of at least once a week of the test chemical during pregnancy
Group 3: No intake

Duration of test:

Not specified.

Remarks:

Not specified

No. of animals per sex per dose:

Group 1: 63 patients
Group 2: 81 patients
Group 3: 63 patients

Details on study design:

The study included three groups. Group 1 consisted of 63 patients with a daily intake of the test chemical by a powder. Group 2 consisted of 81 patients with an intake of the test chemical at least once a week during pregnancy either by the same powders as Group 1 (60% of the patients) or by tablets. None of the patients in Group 1 or 2 took the test chemical for chronic disease, however, they were all habitual users. Group 3 consisted of 63 test chemical-free patients that were matched to Group 1 for age, parity, gravidity, ethnic group, and social class. The incidence of smoking was however significantly higher in Group 1 as compared to Group 3. The incidence of anemia was also significantly higher in Group 1 as compared to Group 3.

Statistics:

Student t test or chi-square test.

Mean gestation length was significantly longer in Group 1 (mean, 39.7 weeks) and Group 2 (mean 39.8 weeks) as compared to Group 3 (mean 38.7 weeks). No significant effects were observed on the number of pregnancies lasting longer than 42 weeks or on the number of premature labors. Labor duration tended to be greater in Group 1 (mean, 5.6 hr) and 2 (mean, 5.5 hr) compared to Group 3 (mean 4.8 hr). Mean birthweight (corrected for: gestation length, being first-born and smoking) was significantly lower in Group 1 babies (mean, 3283 gram) as compared to Group 3 babies (mean, 3502 gram). The incidences of major congenital anomalies were 3, 5 and 2% in Group 1, 2 and 3, respectively. The incidence of stillbirth was significantly increase in Group 1 (5.8%) as compared to Group 3 (1.2%). No significant effect was observed on neonatal mortality; however, the incidence of perinatal death was significantly increased in Group 1 (8.7%) as compared to Group 3 (2.7%).

Conclusions:

Exposure to the test chemical during human gestation was associated with increased gestation length, increaed labor duration, lower birth weight, and increased incidence of perinatal mortality. No adverse effects on teratology were observed. The data needs to be interpreted with caution due to a number of methodological limitations (e.g. controls not matched for anemia or smoking status, and unclear influence of other constituents of the powders to the results).

Executive summary:

The effect of the test chemical on human pregnancy was investigated. The study included three groups. Group 1 consisted of 63 patients with a daily intake of the test chemical during pregnancy by powder. Group 2 consisted of 81 patients with an intake of the test chemical at least once a week during pregnancy either by the same powders as Group 1 or by tablets. None of the patients in Group 1 or 2 took the test chemical for chronic disease, however, they were all habitual users. Group 3 consisted of 63 test chemical-free patients that were matched to Group 1 for age, parity, gravidity, ethnic group, and social class. The incidence of smoking was however significantly higher in Group 1 as compared to Group 3. The incidence of anemia was also significantly higher in Group 1 as compared to Group 3. Mean gestation length was significantly longer in Group 1 (mean, 39.7 weeks) and Group 2 (mean 39.8 weeks) as compared to Group 3 (mean 38.7 weeks). No significant effects were observed on the number of pregnancies lasting longer than 42 weeks or on the number of premature labors. Labor duration tended to be greater in Group 1 (mean, 5.6 hr) and 2 (mean, 5.5 hr) compared to Group 3 (mean 4.8 hr). Mean birthweight (corrected for: gestation length, being first-born and smoking) was significantly lower in Group 1 babies (mean, 3283 gram) as compared to Group 3 babies (mean, 3502 gram). In Group 1 and 2, corrected birthweights were inversely associated with duration of test chemical intake. This indicates that the difference in corrected birthweight between Group 1 and 3 could be due to cumulative secondary effect from maternal factor(s). The incidences of major congenital anomalies were 3, 5 and 2% in Group 1, 2 and 3, respectively. The incidence of stillbirth was significantly increase in Group 1 (5.8%) as compared to Group 3 (1.2%). No significant effect was observed on neonatal mortality; however, the incidence of perinatal death was significantly increased in Group 1 (8.7%) as compared to Group 3 (2.7%). The above data on fetal wastage needs to be interpreted with caution as the authors included data from present and past pregnancies, which is somewhat questionable because the probability of stillbirth and perinatal death may not be independent from pregnancy to pregnancy. The influence of smoke and of other constituents of the powders to the results was not investigated.

Justification for classification or non-classification

Treatment with sodium salicylate in rats is associated with increased labor duration, increased maternal perinatal lethality, increased embryofetal lethality and disrupted fetal development. In rabbits, treatment with a read-across chemical which shares the same active metabolite as sodium salicylate is associated with no adverse effects on development or teratology other than a slight decrease in mean fetal weight observed in the presence of marked maternal toxicity. These findings are consistent with human data that showed no adverse effects on teratology but a similar decrease in mean birthweight following heavy intake of the same read-across chemical during pregnancy. The disparity in developmental effects observed in rats vs. humans may be due to a considerably stronger capacity of the active metabolite to bind to plasma proteins in humans than in rats (see reference in CMR report). If this is the case during pregnancy, rat embryos can be expected to be more heavily exposed to the active metabolite following a given maternal dose than a human embryo would be. Human data have also shown that heavy exposure to the same read-across chemical during pregnancy is associated with increased gestation length and increased labor duration. These findings need to be interpreted with caution as the effects were observed in seriously diseased patients with chronic intake of the read-across chemical for therapeutic reasons. It should also be mentioned that data derived from rats indicate that there might be some qualitative differences in maternal reproductive toxicity profiles between sodium salicylate and the read-across chemical (see reference in CMR report). Sodium salicylate is regarded to be classified as Category 2 for Reproductive toxicity. The decision is based primarily on observed maternal reproductive toxicity in rats following treatment with sodium salicylate during gestation. The significance of these results to the general human population can be questioned as kinetic studies have shown that the active metabolite of sodium salicylate has a considerably stronger capacity to bind to plasma proteins in humans than in rats (see reference in CMR report). This discrepancy is likely to impact the toxicodynamics and/or toxicokinetics of the active metabolite in rats vs. humans.