Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
17 Jul - 26 Aug 1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study with acceptable restrictions (lack of details on test substance; no analytical purity given)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
yes
Remarks:
analytical purity of test substance not specified
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Fatty acids, C8-16, 2-ethylhexyl esters
- Physical state: Yellow liquid
- Analytical purity: no data
- Storage condition of test material: RT
- Density: 0.86 g /cm³
- Stability: stable
- Solubility: insoluble in water

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Age at study initiation: 7 - 12 weeks
- Assigned to test groups randomly: yes
- Housing: 5 animals of each sex in polycarbonate cages
- Acclimation period: 7 - 15 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 26
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
- Vehicle(s)/solvent(s) used: corn oil
Details on exposure:
Dosing volume: 10 mL/kg
Duration of treatment / exposure:
Single dose
Frequency of treatment:
Single dose
Post exposure period:
Up to 72 h
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0, 1250, 2500 and 5000 µL/kg bw
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
0, 1075, 2150 and 4300 mg/kg bw
Basis:
other: calculated based on a density of 860 mg/mL
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide
- Route of administration: intreperitoneal
- Doses / concentrations: 30 mg/kg bw

Examinations

Tissues and cell types examined:
Erythrocytes of the bone marrow
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: Results of a pretest with 50, 160, 500, 1600 and 5000 µL/kg and the sponsor´s specification

DETAILS OF SLIDE PREPARATION: Immediately after sacrife, both femurs of the animal were removed and flushed with a few drops of fetal calf serum onto a clean microscope slide. A second slide was inverted and placed to the first slide. Using a circular motion, the two slides were rubbed together until the bone marrow was evenly dispersed. The two slides were gently pulled appart, air dried, fixed in methanol for approx. 10 min and again air dried.The slides were stained with Giemsa for 5 min and differentiated in distilled water afterwards.

METHOD OF ANALYSIS: at least 1000 polychromatic erythrocytes were counted for each category.
Evaluation criteria:
There should be a statistically significant increase in the number of micronucleated polychromatic erythrocytes in the treatment group over the negative control group.
Statistics:
The two-tailed Student´s t-test was applied to compare the frequency of micronucleated cells to the respective vehicle control.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid

Any other information on results incl. tables

Table 1: Mean numbers of micronucleated cells

Treatment

Micronucleated cells

mean

SD

Vehicle control

2.26

1.41

5000 µL/kg

1.66

1.15

2500 µL/kg

1.93

1.17

1250 µL/kg

1.80

0.81

Positive control

17.20

2.62

There was no significant increase of micronucleated cells in the treatment groups compared to the negative control. The positve control was valid. No indications for mutagenicity in vivo were given.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative