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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: other: chromosome mutation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
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

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
not specified
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name of test material (as cited in study report): Sorbitan monooctadecanoate
- Molecular weight (if other than submission substance): 430.62
- Physical state: white to slightly yellow waxy solid
- Analytical purity: >99.5%
- Storage condition of test material: room temperature

Test animals

Species:
mouse
Strain:
Crj: CD(SD)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Japan
- Age at study initiation: 9 weeks
- Weight at study initiation:23.1-34.5


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0-25.0
- Humidity (%): 40.0-75.0
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: water
Duration of treatment / exposure:
gavage, once per day, two days
Frequency of treatment:
once per day, two days
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
500, 1000 and 2000 mg/kg
Basis:
actual ingested
micronucleus test
Remarks:
Doses / Concentrations:
250, 500, 1000, 2000 mg/kg
Basis:
actual ingested
preliminary toxicity test
No. of animals per sex per dose:
Preliminary toxicity test: 3 males and 3 females per dose
main test: 5 males per dose
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamidemonohydrat
- Route of administration: gavage
- Doses / concentrations: 50 mg/kg

Examinations

Tissues and cell types examined:
bone marrow

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes

Any other information on results incl. tables

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.

General condition and mortality in mice after double oral administrations of sorbitan stearate in the preliminary toxicity test

 sex  Dose mg/kg/day  Number of mice  General condition  Mortality
          male  250  3   no abnormality   0/3
 500  3   no abnormality   0/3
 1000  3    no abnormality   0/3
 2000  3    no abnormality   0/3
          female  250  3    no abnormality   0/3
 500  3    no abnormality   0/3
 1000  3    no abnormality   0/3
 2000  3    no abnormality   0/3

General conditin and mortality in male mice after double administration of sorbitan stearate in the micronucleus test

 Dose mg/kg/day  Number of mice  General condition  Mortality
 Negative control  5    no abnormality   0/5
 500  5    no abnormality   0/5
 1000  5    no abnormality   0/5
 2000  5    no abnormality   0/5
 positive coontral 50  5    no abnormality   0/5

Results of micronucleus test in male mice after double oral administrations of sorbitan stearate

 Group  Animal No.  % of MNPCEs  % of PCEs in ERY
 Negative control  1  0.10 56.7 
 2  0.05 47.8 
 3  0.15 53.5 
 4 0.10 62.6 
 5  0.15  40.0
 mean  0.11  52.1
 500 mg/kg/day  6  0.00 59.4 
 7  0.10 62.2 
 8  0.20 57.8 
 9  0.10 52.3 
 10  0.05 55.0 
  mean  0.09 57.3 
 1000 mg/kg/day                  11  0.20 57.4 
 12  0.10 50.8 
 13  0.15 50.4 
 14  0.05 58.6 
 15  0.10 43.9 
  mean  0.12 52.2 
 2000 mg/kg/day                  16  0.05 63.8 
 17  0.15 56.4 
 18  0.30 65.1 
 19  0.05 52.9 
 20  0.10 52.4 
  mean  0.13 58.1 
Positive control 50 mg/kg/day                  21  2.75  59.4
 22 2.45 57.7 
 23 2.75  60.5 
 24  2.65 59.1 
 25  3.00 66.5 
  mean  2.72 60.6 

 % of MNPCEs: % of micronucleated polychromatic erythrocytes in polychromatic ery血rocytesobserved

 % of PCEs in ERY: % of polychromatic erythrocytes in erythrocytes observed

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
In conclusion, the test item did not induce clastogen effect in the bone marrow cells of the mouse under the test condition.
Executive summary:

The test item was asssessed in the micronucleus assay for its potential to induce micronuclei in the bone marrow of mice. Water was used as a vehicle. Preliminary toxicity test was carried out in order to test the dose used, with doses of 250, 500, 1000, 2000 mg/kg/day in male and female mice by gavage. No mortality or abnormality was observed. Therefore the micronucleus test was performed with doses of 500, 1000, 2000 mg/kg/day. The test item was administered by gavage once per day for 2 days. Water was used as negative control and CP was used as positive control. No effect was observed in the groups of the test substance. Significant effects were observed in the postive control group. In conclusion, the test item did not induce clastogen effect in the bone marrow cells of mice under the test condition.