Registration Dossier

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20 days study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data

Data source

Reference
Reference Type:
review article or handbook
Title:
Unnamed
Year:
2014
Report Date:
2014

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Version / remarks:
The actual details of the guideline followed were not included in the report. From the details given, it is concluded that the OECD method has been followed
Principles of method if other than guideline:
Dosage calculations were based on a 100% active component. Since the test substance was received with a 30.4% active moiety in 10% ethanol, a correction factor of 3.2895 was utilized to achieve the proper amount of active ingredient. The control group received ethanol in deionized water at a volume of 5 ml/kg. The amount of ethanol the control group received was equal to the amount given to the 250 mg/kg/day group. The stock solution was prepared daily. Dose volume was 5 ml/kg body weight, adjusted for body weight on days of gestation 6, 9 and 12. Animals were observed twice daily for signs of toxicity. Body weights were recorded on day 0, 6, 9, 12, 16 and 20 of gestation. Food consumption intervals were identical to the body weight intervals. On gestation day 20, all surviving females were sacrificed by carbon dioxide inhalation. The uterus was exposed and the lumber and location of viable and nonviable fetuses, early and late resorptions and the number of total implantations and corpora lutea were recorded. The uterus was then excised and the fetuses were removed. Live fetuses were individually weighed, sexed, tagged and examined for external malformations or developmental variations. Approximately one half of the fetuses for each litter were fixed in Bouin's solution to examine the viscera and brain by Wilson's sectioning technique. The remaining one-half of the fetuses were processed (alizarin red staining) and examined for skeletal abnormalities.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
30.4% active cetyl betaine in 10% ethanol (correction factor of 3.2895 was utilized to achieve proper amount of active ingredient)

Test animals

Species:
rat
Strain:
Sprague-Dawley

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
ethanol
Duration of treatment / exposure:
The rats received the test material daily for 10 days starting on gestation day 6.
Frequency of treatment:
The rats received the test material daily for 10 days starting on gestation day 6.
Duration of test:
Total duration was 20 days
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day
Dose / conc.:
50 mg/kg bw/day
Remarks:
received 50 mg/kg /day of 30.4% active cetyl betaine in 10% ethanol (correction factor of 3.2895 was utilized to achieve proper amount of active ingredient)
Dose / conc.:
150 mg/kg bw/day
Remarks:
received 150 mg/kg /day of 30.4% active cetyl betaine in 10% ethanol (correction factor of 3.2895 was utilized to achieve proper amount of active ingredient)
Dose / conc.:
250 mg/kg bw/day
Remarks:
received 250 mg/kg /day of 30.4% active cetyl betaine in 10% ethanol (correction factor of 3.2895 was utilized to achieve proper amount of active ingredient)
Control animals:
yes
Details on study design:
The animals were observed twice daily for signs of toxicity and body weights and feed consumption were recorded on day 0, 6, 9, 12, 16, and 20 of gestation. On gestation day 20, all surviving rats were killed and the uterus and the fetuses were examined and measured for number and location of viable and nonviable fetuses, early and late resorptions, number of total implantations and corpora lutea, fetal body weights, sex, external malformations or developmental variations, and skeletal abnormalities. Microscopic examination of the parental reproductive organs not described.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
No deaths occurred in any dams in the control or treated groups. Clinical observations noted in animals dosed at 250 mg/kg/day included stained and matted fur (noted primarily on the limbs, neck, ventral thorax and facial area), excessive salivation, respiratory rales, diarrhea, decreased activity, hypothermia, lacrimation, labored breathing and wheezing. Similar observations were evident at 150 mg/kg/day group, stained and mattered fur and respiratory rales were the predominant observations. A dose-related trend of maternal body weight inhibition was noted during both the overall gestation (days 0 - 20) and
treatment (days 6 - 15) periods at all dose levels. Weight loss was observed during the first treatment interval (days 6 - 9) at 150 and 250 mg/kg/day. Reduced food intake was also noted among all treated groups during the treatment period in an apparent dose-related trend. In addition, consumption was inhibited at 250 mg/kg/day during the overall gestation interval but mean values of the 50 and 150 mg/kg/day groups were comparable to controls. Necropsy revealed no treatment-related differences among the groups.
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Inhibition of maternal body weight gain was observed as a dose-related trend during overall gestation and the treatment periods at all dose levels. Weight loss was observed during the first treatment interval in the 150 and 250 mg/kg dose groups. Decreased feed consumption was also observed in all treated groups during the treatment period in a dose-dependent manner. .
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
Feed consumption was noted to be inhibited at 250 mg/kg during the overall gestation period, but the mean values for the 50 and 150 mg/kg dose groups were comparable to controls

Maternal developmental toxicity

Number of abortions:
no effects observed
Total litter losses by resorption:
no effects observed
Dead fetuses:
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): no effects observed

Effect levels (maternal animals)

Dose descriptor:
LOAEC
Effect level:
50 mg/kg bw/day
Based on:
act. ingr.
Basis for effect level:
body weight and weight gain

Maternal abnormalities

Abnormalities:
no effects observed

Results (fetuses)

Fetal body weight changes:
not specified
Description (incidence and severity):
In the fetuses, no significant differences between the control and treated groups were evident with respect to number of corpora lutea, total implantations, post implantation loss, viable fetuses, and fetal body weights. Fetal malformation in the treated groups was not significantly different from that of the controls. Reduced or absent ossification of the skull, sternebrae #5 and/or #6, and other sternebrae occurred more frequently in the 250 mg/kg dose group. These effects were considered to be biologically significant as they were observed in conjunction with reduced maternal body weight gains. No other developmental variations were noted.

Effect levels (fetuses)

Dose descriptor:
LOAEL
Effect level:
250 mg/kg bw/day
Based on:
act. ingr.
Basis for effect level:
other: developmental

Fetal abnormalities

Abnormalities:
no effects observed
Description (incidence and severity):
Reduced or absent ossification of the skull, sternebrae #5 and/or #6, and other sternebrae occurred more frequently in the 250 mg/kg dose group. These effects were considered to be biologically significant as they were observed in conjunction with reduced maternal body weight gains.

Overall developmental toxicity

Developmental effects observed:
yes
Lowest effective dose / conc.:
250 mg/kg bw/day
Treatment related:
not specified
Relation to maternal toxicity:
not specified
Dose response relationship:
yes
Relevant for humans:
not specified

Applicant's summary and conclusion

Conclusions:
In oral reproductive and developmental toxicity studies of cetyl betaine in rats, the LOAEL for the dams was 50 mg/kg due to decreased body weight gain and a maternal NOAEL could not be calculated. The developmental LOAEL was 250 mg/kg and the developmental NOAEL was 150 mg/kg.