Registration Dossier

Administrative data

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.

Data source

Reference
Reference Type:
publication
Title:
Maternal reproductive effects of the given test chemical in Sprague-Dawley rats
Author:
Davis et al.
Year:
1996
Bibliographic source:
Toxicology Letters

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Crystal powder
Details on test material:
- Name of test material (as cited in study report): Sodium salicylate
- Molecular formula : C7H5NaO3
- Molecular weight : 160.10467
- Substance type: Organic
- Physical state: Solid

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on species / strain selection:
No data available
Sex:
female
Details on test animals 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

Administration / exposure

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.
Doses / concentrations
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.

Examinations

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

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

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 / performance (P0)

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.

Effect levels (P0)

open allclose all
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

Results: F1 generation

General toxicity (F1)

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..

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not examined

Effect levels (F1)

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

Overall reproductive toxicity

Reproductive effects observed:
not specified
Treatment related:
not specified

Any other information on results incl. tables

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*

 

 

Applicant's summary and conclusion

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.