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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
2012-02-19 to 2012-03-08
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Qualifier:
according to
Guideline:
EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)
Qualifier:
according to
Guideline:
EU Method B.31 (Prenatal Developmental Toxicity Study)
Qualifier:
according to
Guideline:
other: Japanese Ministry of Agriculture, Forestry and Fisheries Testing Guidelines for Toxicology Studies 12 NohSan No. 8147 (2000-11-24)
GLP compliance:
yes (incl. certificate)
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
Batch No.: 20111009
Purity: 99.29%

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River (UK), Margate, Kent, United Kingdom
- Age at study initiation: Approx. 10-12 wks
- Weight at study initiation: 194 g to 303 g
- Fasting period before study:
- Housing: Individually in solid floor polypropylene cages with stainless steel lids furnished with softwood flakes
- Diet: Pelletted diet ad libitum
- Water: Mains drinking water ad libitum
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature: Targeted to 21 °C ± 2 °C
- Humidity: Targeted to 55 % ± 15 %
- Air changes: ≥ 15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
arachis oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The test item was prepared at the appropriate concentrations as a solution in Arachis oil.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Non-GLP study; see attached supporting information
Details on mating procedure:
Time-mated, no further details provided. The day that positive evidence of mating was observed was designated as Day 0 of gestation.
Duration of treatment / exposure:
From day 5 to day 19 of gestation.
Frequency of treatment:
Daily
Duration of test:
Animals killed on day 20.
Doses / concentrationsopen allclose all
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
24 Females per dose (0 males)
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Based on previous toxicity data
- Rationale for animal assignment: Randomised based on stratified body weights.

Examinations

Maternal examinations:
DETAILED CLINICAL OBSERVATIONS:
- Time schedule: Gestation period - daily. Dosing period - immediately before dosing, soon after dosing, 1 hr post dosing. Additional observation 5 hr post dosing during working week.

BODY WEIGHT:
- Time schedule for examinations: Day 3 (before start of treament), days 5, 6, 7, 8, 11, 14, 17, 20.

FOOD CONSUMPTION:
- Time schedule for examinations: Day 3 (before start of treament), days 5, 6, 7, 8, 11, 14, 17, 20.

WATER CONSUMPTION
- Time schedule for examinations: Recorded per animal for consecutive 3 d periods.

POST-MORTEM EXAMINATIONS:
- Sacrifice on gestation day 20
- Organs examined: Ovaries and uteri
Ovaries and uterine content:
- Parameters examined: Corpera lutea, number position and type of intrauterine implantation, foetal sex, external foetal appearance, foetal weight, placental weight, gravid uterus weight
- Implantation types divided into categories as follows: (1) early death ( no visible distinction between placental/decidual tissue and embryonic tissue); (2) late death (separate embryonic/foetal and placental tissue visible); (3) dead foetus (died shortly before necropsy; included as late deaths for reporting purposes)
Fetal examinations:
The foeti were killed by subcutaneous injection of sodium pentobarbitone. Foeti from each litter were divided into 2 groups and examined for skeletal alterations and soft tissue alterations. Alternative foeti were identified using an indelible marker and placed in Bouin's fixative. Foeti were transferred to a 90 % industrial methylated spirits (IMS) in distilled water and examined for visceral abnormalities under a low power binocular microscope. The remaining foeti were eviscerated, processed and the skeletons stained with alizqarin red. The foeti were examined for skeletal development and abnormalities. Following examination foeti that were examined for skeletal development were placed in 100 % gylcerol.
Statistics:
- Female body weight change, food consumption and gravid uterus weight: Bartlett's test for homogeneity of variance and 1-way analysis of variance followed by Dunnett's multiple comparison test or, if unequal variances observed, on alternative multiple comparison test
- All caesarean necropsy parameters and foetal parameters: Kruskal-Wallis non-parametric analysis of variance and a subsequent pairwise analysis of control values against treated values using the Mann-Whitney U test where significance was seen.
- Foetal evaluation parameters, including skeletal or visceral findings: Kruskal-Wallis non-parametric analysis of variance and Mann-Whitney U test.
Indices:
- Pre and post-implantation loss.
- Sex ratio.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Description (incidence and severity):
No clinically observed signs of toxicity were detected in animals throughout the study period.
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
- No toxicologically significant effects on body weight development were detected.
- Females treated with 1000 mg/kg bw/d and 300 mg/kg bw/d showed a statistically significant increase in body weights between days 6-7. Females treated with 300 mg/kg bw/d continued to show an increase in body weight gain between days 8-11 and 14-20. Subsequent cumulative body weight gain in females treated with 300 mg/kg bw/d was increased from day 11 onwards when compared to controls. Females from this treatment group also showed a statistically significant increase in body weight on day 20 and in gravid uterus weight. Increases in these parameters were not considered to represent an adverse effect of treatment and in the absence of true dose-related responses, the intergroup differences were considered not to be of toxicological significance.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
- No toxicologically significant effects on dietary intake were detected.
- Females treated with 300 mg/kg bw/d showed a statistically significant increase in food consumption from day 5 onwards. Females treated with 1000 mg/kg bw/d also showed a statistically significant increase in food consumption between days 14 and 17. An increase in the parameter was not considered to represent an adverse effect of treatment and in the absence of a true dose-related response the, the intergroup difference was considered not to be of toxicological significance.
Water consumption and compound intake (if drinking water study):
no effects observed
Description (incidence and severity):
- No adverse effect on water consumption was detected.
- Statistical analysis did not reveal any significant differences.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
Animals treated with 300 mg/kg bw/d showed a statistically significant increase gravid uterus weight when compared to control animals. An increase in this parameter was not considered to represent an adverse effect of treatment and in the absence of a true dose-related response the intergroup difference was considered not to be of toxicological significance.
Gross pathological findings:
no effects observed
Description (incidence and severity):
No treatment-related macroscopic findings were dected in treated females.

Effect levels (maternal animals)

Key result
Dose descriptor:
NOEL
Effect level:
1 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal developmental toxicity

Results (fetuses)

Reduction in number of live offspring:
no effects observed
Description (incidence and severity):
There was no adverse effect on in utero offspring survival, as assessed by the mean numbers of early or late resorptions, live litter size and implantation loss.
Changes in litter size and weights:
no effects observed
Description (incidence and severity):
There was no adverse effect on in utero offspring survival, as assessed by the mean numbers of early or late resorptions, live litter size and implantation loss.
External malformations:
effects observed, non-treatment-related
Description (incidence and severity):
For all dose groups there were no significant treatment-related trends in the proportion of foeti or litters with evidence of visceral or skeletal abnormalities. The type of visceral and skeletal abnormalities seen were those commonly observed in this type of study.
Skeletal malformations:
effects observed, non-treatment-related
Description (incidence and severity):
For all dose groups there were no significant treatment-related trends in the proportion of foeti or litters with evidence of visceral or skeletal abnormalities. The type of visceral and skeletal abnormalities seen were those commonly observed in this type of study.
Visceral malformations:
effects observed, non-treatment-related
Description (incidence and severity):
For all dose groups there were no significant treatment-related trends in the proportion of foeti or litters with evidence of visceral or skeletal abnormalities. The type of visceral and skeletal abnormalities seen were those commonly observed in this type of study.

Effect levels (fetuses)

Key result
Dose descriptor:
NOEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: developmental toxicity

Overall developmental toxicity

Key result
Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The oral administration of the test substance to pregnant rats was performed according to OECD Guideline 414. Rats dosed by oral gavage during organogenesis at dose levels of 100, 300 and 1000 mg/kg bw/day did not result in any toxicologically significant effects at any dose level. The NOEL was therefore considered to be 1000 mg/kg bw/day. No toxicolofically significant changes were detecetd in the offspring parameters measured. The NOEL for reproductive and developmental toxicity was therefore considered to be 1000 mg/kg bw/day. The NOAEL was considered to be greater than 1000 mg/kg bw/day.