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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
Guideline study under GLP

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2000
Report date:
2000

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes
Limit test:
no

Test material

Constituent 1
Reference substance name:
2-ethylhexyl stearate
EC Number:
244-754-0
EC Name:
2-ethylhexyl stearate
Cas Number:
22047-49-0
Molecular formula:
C26H52O2
IUPAC Name:
2-ethylhexyl octadecanoate
Test material form:
liquid
Details on test material:
2-Ethylhexyl stearate is a colourless and odourless liquid. It is insoluble in water and this UVCB substance has a relative density of 0.86 g/cm3 and a mean molecular weight of 390 g/mol.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals or test system and environmental conditions:
TEST ANIMALS:
- Source: Charles River, Wiga GmbH, Sulzfeld, Germany
- Age at study initiation: 8, weeks
- Weight at study initiation: 195-199 g
- Fasting period before study: no data
- Housing: semi-barrier sustained animal room, individually in Markrolon type M3 cages
- Diet (e.g. ad libitum): Altromin No. 1324, Altromin GmbH, Lage, Germany, ad libitum
- Water (e.g. ad libitum): community tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-23
- Humidity (%): 40-56
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To:

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: arachidis oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): daily
- Mixing appropriate amounts with (Type of food):
- Storage temperature of food:

VEHICLE
- Justification for use and choice of vehicle (if other than water): optimal solubility
- Concentration in vehicle:
- Amount of vehicle (if gavage):
- Lot/batch no. (if required): arachidis oil, DAB 10
- Purity:PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency):
- Mixing appropriate amounts with (Type of food):
- Storage temperature of food:

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Concentration in vehicle:
- Amount of vehicle (if gavage): 5 ml/kg body weight
- Lot/batch no. (if required):
- Purity:
Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
Animals were cohabitated 1:1, and females were examined every morning for the presence of sperm in the vaginal canal or a vaginal plug; this was designated GD0 of gestation.
Duration of treatment / exposure:
GD 6-15
Frequency of treatment:
once daily
Duration of test:
20 days
Doses / concentrationsopen allclose all
Dose / conc.:
100 mg/kg bw/day (nominal)
Dose / conc.:
300 mg/kg bw/day (nominal)
Dose / conc.:
1 000 mg/kg bw/day (nominal)
No. of animals per sex per dose:
24
Control animals:
yes, concurrent vehicle
Details on study design:
Animals were randomly assigned to test groups using random tables. They were treated and euthanised (ether) on GD20 in accordance with Animal Welfare legislation and guidelines. Foetuses were removed by Caesarian section.

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: GD0, 6, 16 and 20

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on GD20
- Organs examined: Gross macroscopic examination of all maternal organs, with emphasis on uterus, uterine contents, position of the foetuses and presence of corpora lutea, and pre- and post-implantations

OTHER:
Ovaries and uterine content:
Examination was made of each animal's uterus, uterine contents, position of the foetuses and presence of corpora lutea, and pre- and post-implantations. The pre-implantation and post-implantation loss and intrauterine resorption sites were evaluated. Intrauterine deaths were classified on the basis of the absence (early resorption) and of the presence (late resorption) of foetal or decidual tissue in addition to placental tissue.
Fetal examinations:
Living and dead foetuses were removed from the uterus. The living foetuses were sexed, weighed individually with placentae and examined for gross external abnormalities. Foetal soft tissue and skeletal developmen t were investigated. The Wilson technique was applied to half of the foetuses to evaluate potential visceral changes (Wilson and Warkany, 1965). The remaining foetuses were cleared in a solution of potassium hydroxide and stained with Alizarin Red according to Dawson (1926). Alterations in foetuses were classified according into four categories (Klimisch et al., I992).
Statistics:
If the variables could be assumed to follow a normal distribution, the Dunnett test, based on a pooled variance, was applied for the comparison between the treated groups and the control group. The Steel test was applied when the data could not be assumed to follow a normal distribution. Fisher's exact test for 2 x 2 tables was applied if the variables could be dichotomized without loss of information (Bonferroni - Holm corrected).
Indices:
not specified

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
no effects observed
Details on results:
2-Ethylhexyl stearate did not cause adverse effect to the maternal rats at any time during the pregnancy. No mortalities occurred in the dams during the study, either in the vehicle control or in the groups exposed to 2-ethyl­hexyl stear te up to 1000 mg/kg body weight. The absolute and the corrected body weight (Table 2) and body weight gain was comparable between the groups. No deviation was observed during the treatment period. Gross macroscopic examination of the maternal organs including ovaries and uterus revealed no alterations. The no-adverse-effect dose of 1000 mg/ kg body weight corresponds to the NOAEL of the repeated dose toxicity data in rats.

Maternal developmental toxicity

Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Description (incidence and severity):
In the 100 and 1000 mg/ kg body weight groups the post-implantation loss and total embryonic deaths were significantly decreased.
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined
Changes in number of pregnant:
no effects observed
Other effects:
no effects observed

Effect levels (maternal animals)

Key result
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Basis for effect level:
other: no adverse effects noted
Remarks on result:
not determinable due to absence of adverse toxic effects

Maternal abnormalities

Key result
Abnormalities:
no effects observed

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
not examined
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Other effects:
not examined
Details on embryotoxic / teratogenic effects:
The weights of live foetuses exhibited no significant differences on a litter and individual basis. In comparison with the control group, in the 100 and 1000 mg/ kg body weight groups the post-implantation loss and total embryonic deaths were significantly decreased. Non-dose-related findings were considered to be incidental, compared to control values. Mean foetal placental and uterus weights were not affected by treatment. Foetal sex ratio was comparable in all groups. A hydrops was noted in one control group foetus.

Incidences were also compared to the historical controls of the OECD guideline No. 414 studies using the same strain (Sprague-Dawley CD). Findings both on the individual foetus and on the litter basis did not differ from the historical control. From the visceral examinations, one hydrocephalus internus was found which has to be considered as an individual non-dose-related finding which also occurs in the historical data at a comparable level (0.4 %). All other changes were slight and also occurred in the control population. Concerning the skeletal examinations on the basis of the foetal incidence, there are differentiated results in some findings such as 'non-ossification' of sternebrae (retardation). However, the total frequency of the findings 'incomplete ossification' including 'non-ossification' of all sternebrae show no substantial differences between the untreated and treated groups.I

Effect levels (fetuses)

Key result
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no adverse effects noted
Remarks on result:
not determinable due to absence of adverse toxic effects

Fetal abnormalities

Key result
Abnormalities:
no effects observed

Overall developmental toxicity

Key result
Developmental effects observed:
no

Applicant's summary and conclusion

Conclusions:
In a guideline OECD 414 developmental toxicity study of 2-ethylhexyl stearate in CD rats at 100, 300 and 1000 mg/kg bw/d in arachidis oil, no adverse maternal effects, fetotoxic effects or teratogenic effects or variations were observed. The NOAEL for maternal toxicity is > 1000 mg/kg bw/d, and the NOAEL for developmental toxicity is > 1000 mg/kg bw/d. The substance is not classified for developmental effects according to Regulation EC No. 1272/2008.