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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Justification of read-across: Both chemicals are of comparable structures with minor deviations and can be characterized as an ester of sorbitan and a fatty acid. Justification of reliability of 2: scientifically well-performed study

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
1956
Report Date:
1956
Reference Type:
publication
Title:
Unnamed
Report Date:
1956
Reference Type:
publication
Title:
Unnamed
Year:
1957
Report Date:
1956

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
other: OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Deviations:
yes
Remarks:
4 generations investigated
GLP compliance:
no
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Test material form:
not specified
Details on test material:
- Name of test material (as cited in study report): Span 60

Test animals

Species:
rat
Strain:
Wistar
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Food Research Laboratories
- Age at study initiation: 4 x wks; (F1) x wks
- Weight at study initiation: 50-70 g
- Housing: For the first 12 weeks, hosed individually, when mating, transferred to larger cages, one male housed with one or two females
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23-26
- Humidity (%): 40-60

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Analytical verification of doses or concentrations:
no
Details on mating procedure:
- M/F ratio per cage: 1/1 or 1/2
- Length of cohabitation: maximum 3 weeks, if pregnancy ont established, the male was replaced.
- Proof of pregnancy: bisuall, by palpation, or from weight increments
- After 21 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: yes, following 3 (occasionally 4) unproductive tirals with females of knon fertility, males were considered sterile and retired. Females were continued for a minimum of 6 matings with fertile males, even though somne failures may have intervened.
- After successful mating each pregnant female was caged (how): individually
Duration of treatment / exposure:
2 years
Frequency of treatment:
feed, continuously
Duration of test:
2 years
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 5, 10, 20 %
Basis:
nominal in diet
No. of animals per sex per dose:
12 males, 20 females
Control animals:
yes, plain diet

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: no data
- Cage side observations checked: physical appearance, behavior, laxation and water consumption.

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: weekly during the first 12 weeks, biweeksly thereafter

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for 5 animals each sex determined for the first 12 weeks, and for a two week period at the 0.5 1, 1.5, and 2-year stages in the initial generation and for 12 weeks after weaning in succeeding generations.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes
SACRIFICE
- Male animals: All surviving animals
- Maternal animals: All surviving animals

GROSS NECROPSY
- all animals

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues: kidney and liver, other organs were examined microscopically where indicated by their gross appearance and in at leat two apparently normal rats of each sex randomly selected from the 20% groups.

Fetal examinations:
viability index (V.l.), the percentage of rats born that survived 4 days or longer;
lactation in dex (L.I.), the percentage of rats alive at 4 days that survived the 21-day lactation period.

SACRIFICE
- Male animals: All surviving animals
- Maternal animals: All surviving animals

GROSS NECROPSY
- all animals

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues: kidney and liver, other organs (stomach, thyroid, gonads, lymph nodes, bone marrow and spinal cord) were examined microscopically where indicated by their gross appearance and in at leat two apparently normal rats of each sex randomly selected from the 20% groups.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
- no effect

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
- in the 20% dose group of males, the body weight gain in 12-week was lower than control group
- no effect in food consumption

ORGAN WEIGHTS (PARENTAL ANIMALS), GROSS PATHOLOGY (PARENTAL ANIMALS), HISTOPATHOLOGY (PARENTAL ANIMALS):

- In 20% group, liver enlargement was observed; histopathologically these livers showed moderate central or lobular necrosis.
- In 10 and 20% group, the kidney weighs were increased; but no organic changes were seen microscopically in there kidneys.
- No treatment related effect in other organs examined (stomach, thyroid, gonads, lymph nodes, bone marrow and spinal cord).

Blood observations
The blood hemoglobin levels were within the normal range throughout the entire test and for all groups,
The mean values for total leukocyte counts fell within normal limits. No evidence of eosinophilia was observed although the counts varied within rather wide limits.
No deviations from the ranges of normal blood sugar valueswere found
The average cholesterol levels were normal regardless of the duration of the feeding period or the diet fed and that no trend either upward or downward was observed from one generation to another.

Urine examinations.
The presence of oxalates in the two-year urine specimens was not significantly increased.

Digestibility of fatty acid moieties examination:
The coefficient of digestibility of the test tem was found to be 53.5, and this value was used in computing the caloric value of the supplemented diets for the animals.

Effect levels (maternal animals)

open allclose all
Dose descriptor:
LOAEL
Effect level:
10 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Dose descriptor:
LOAEL
Effect level:
5 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Dose descriptor:
LOAEL
Effect level:
10 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: developmental toxicity
Dose descriptor:
NOAEL
Effect level:
5 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

Decreased growth and viability were noted in offspring born to dams treated at 20% level.

The analogue approach using sorbitan stearate as source chemical is justified:

Both chemicals are of comparable structures with minor deviations and can be characterized as an ester of sorbitan and a fatty acid. Compared to the source chemical, the target chemical has a shorter alkyl chains that affect its physicochemical properties. But based on the kinetic / metabolic investigations on both chemicals, the length of the alkyl chain is not considered to have significant impact on the metabolic pathway or toxicological mode of action. Oral gavage studies in rats administered C14 labeled sorbitan stearate in oil solutions have demonstrated that about 90% of the substance was absorbed and hydrolyzed to stearic acid and sorbitan. The metabolic fate of sorbitan caprylate was investigated using a lipase assay. The hydrolysis mediated by porcine pancreas lipase was quantitatively determined. The target chemical sorbitan caprylate is proved to be hydrolyzed and caprylic acid was formed . These findings suggest that metabolism of the sorbitan occur initially via enzymatic hydrolysis, leading to sorbitan and the corresponding natural acids.

Based on the above mentioned information, it is reasonable to consider that these two substances are comparable in their metabolic fate and thereby toxicological profiles. Hence, the source chemical is considered as “suitable with interpretation” analog.

According to the available toxicity studies, the findings are also comparable for target and source chemicals:

·        The findings in acute toxicity studies are comparable. Both chemicals are of no acute toxicity.

·        The findings in subacute dose toxicity studies are comparable. No treatment effects were observed in 28-day repeated toxicity studies in Wistar rats. The same NOEL of 1000 mg/kg bw/d was derived for both chemicals.

·        The findings in genetic toxicity are comparable. Both chemicals did not induce gene mutations in Ames tests, but induced structural chromosomal aberrations in cell lines of Chinese Hamster.

·        The findings in reproduction / developmental toxicity studies are comparable.

Applicant's summary and conclusion

Conclusions:
The LOAEL and NOAEL of the target chemical are considered to be 10000 and 5000 mg/kg bw/day, respectively.
Executive summary:

The developmental toxicity of sorbitan caprylate was assessed based on the analogue approach using sorbitan monostearate as a read-across supporting substance.

Wistar rats (25 groups consisting of 12 males and 20 females/dose; F0 generation) were administered with sorbitan monostearate in the diet at 0, 5, 10 or 20% (~ 0, 2500, 5000 or 10,000 mg/kg-bw/day) for two years (spanning four generations). During the course

of the study, observations were made of physical appearance, behavior, reproduction, and lactation through three successive generations, and gross and histologic evaluations were made at termination. Growth was normal, except for males in the 20 percent group. These animals had reduced weight gains. Fertility and gestation parameters for the initial generation were similar for control

and test groups. Infant deaths for the 10 and 20 percent ester groups were higher than for the control group. The author believed this was due to maternal neglect and reduced milk production. Reproduction and lactation data were also recorded for the F, and F1 generations. The proportions of matings resulting in pregnancy were lower in the 20 percent dietary ester group, as was the proportion of nurselings surviving the lactation period. No deviation from the normal range was found in hemoglobin values, leukocyte counts, blood sugar, or plasma cholesterol values. Urinalysis after 1 and 2 years had sporadic positive tests for the presence of albumin and reducing sugars. No striking differences in number of deaths in any group were found up to 1% years. However, during the last quarter of the study the number of deaths was greater for the 20 percent group. Lungs of both test and control animals were congested. In rats of the 10 and 20 percent ester groups, the livers were enlarged, but the incidence of hepatic necrosis was no greater in these groups than in lower dosed groups or controls. Also at the two higher dietary concentrations, the weights of the kidneys were increased, but no microscopic changes were observed. The stomach, GI tract, heart, spleen, pancreas, adrenals, thyroid, gonads, lymph nodes, bone marrow, and spinal cord had no compound-related lesions. The investigators concluded

that chronic consumption of a few tenths of 1 percent of Sorbitan Stearate would pose no hazard to human health.

Based on the result, it was concluded:

LOAEL (maternal toxicity) ~10,000 mg/kg-bw/day (based on body weight change, liver enlargement)

NOAEL (maternal toxicity) ~ 5,000 mg/kg-bw/day

LOAEL (reproductive toxicity) ~ 10,000 mg/kg-bw/day (based on decreased reproductive performance and pregnancy rate)

NOAEL (reproductive toxicity) ~ 5,000 mg/kg-bw/day

LOAEL (developmental toxicity) ~ 10,000 mg/kg-bw/day (based on decreased growth of offspring)

NOAEL (developmental toxicity) ~ 5,000 mg/kg-bw/day