Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals and environmental conditions:
Charles River Deutschland GmbH, 97633 Sulzfeld,
Weight at study initiation: m: 23 days (at start of adaptation) / 22-26 g (at administration), f: 24 days (at start of adaptation) / 20-25 g (at administration)
Photoperiod (hrs dark / hrs light): 12/12;
Housing: 5 animals per cage, identification by coloured marks and cage labels;
Temperature (°C):22°C ± 3°C;
Humidity (%): 55% ± 15% relative humidity;
Food and water: ad libitum, feeding was discontinued approx. 16h before administration of the test item

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Duration of treatment / exposure:
Single oral application
Frequency of treatment:
Single oral application
Post exposure period:
24 h (all dose levels including vehicle and positive controls) and 48 h (all dose levels except the positive controls) after treatment.
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 30, 100 and 300 mg/kg bw
Basis:
nominal conc.
Test substance concentration in vehicle: 0, 1.5, 5 and 15 mg/ml (0, 0.15, 0.5, and 1.5%)
No. of animals per sex per dose:
5 m + 5 f per dose and sampling time
Control animals:
yes
Positive control(s):
Vehicle control: Corn oil 20 ml/kg b.w. (oral, by gavage)
Positive control: cyclophosphamide, 27 mg/kg b.w. (i.p., 20 ml/kg b.w.)

Examinations

Tissues and cell types examined:
Bone marrow; Erythrocytes
1000 red blood cells (RBC) for the ratio of polychromatic (PCE) to normochromatic erythrocytes (NCE)
2000 PCE for the incidence of micronuclei
Evaluation criteria:
PCE / NCE ratio
Number of micronuclei in PCE per 1000 RBC
Statistics:
Chi-square test corrected for continuity according to Yates.

Results and discussion

Test results
Key result
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
No signs of toxicity at 30 and 100 mg/kg b.w.; Reduced motility, ataxia and dyspnoea at 300 mg/kg b.w. (30-60 min after administration)
Vehicle controls validity:
valid
Negative controls validity:
not specified
Positive controls validity:
valid

Any other information on results incl. tables

Preliminary dose-range-finding study: Toxic effects at 250 mg/kg b.w. (reduced motility, ataxia and dyspnoea) more pronounced at 500 mg/kg b.w.; 1000 mg/kg b.w. was lethal Main study: No signs of toxicity at 30 and 100 mg/kg b.w.; Reduced motility, ataxia and dyspnoea at 300 mg/kg b.w. (30-60 min after administration).

The PCE / NCE ratio was not significantly altered by treatment with the test item, compared to the concurrent vehicle controls. The ratios were within the range of the historical vehicle control data of the same laboratory

Applicant's summary and conclusion

Conclusions:
Under the restrictions of the assay the test substance is not considered to be mutagenic in PCE of the bone marrow of NMRI mice. No classification is indicated a according to Regulation (EC) No 1272/2008.
Executive summary:

In a study according to OECD guideline 474 and GLP 5 male + 5 female NMRI mice per dose and sampling time were used; mice received a single oral application via gavage at dose levels of 0, 30, 100 and 300 mg/kg bw (0, 0.15, 0.5, and 1.5% in corn oil). 24 h (all dose levels including vehicle and positive controls) and 48 h (all dose levels except the positive controls) after treatment mice were sacrificed and bone marrow prepared. There are valid positive and vehicle controls. Cyclophosphamide as positive control induced a significant increase in micronucleus formation in both m and f. The negative controls lie within in the range of historical negative controls. Under the conditions of this assay the test substance did not induce a significant increase in the number of micronuclei at dose levels up to 300 mg/kg b.w. in both m and f, with 300 mg/kg b.w. mediating marked toxicity. The ratio of PCE / NCE was also not significantly altered by treatment of animals with the test substance.