Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)
Version / remarks:
1992
GLP compliance:
yes
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:
TEST ANIMALS
- Source: Harlan-Winkelmann GmbH, Borchen, Germany
- Fasting period before study: 16 hours
- Housing: individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 6 days



Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: water (aqua ad niectabilia)
- Amount of vehicle (if gavage or dermal): 10 ml/kg bw
Duration of treatment / exposure:
single dose
Frequency of treatment:
single dose
Post exposure period:
sampling time 24 and 48 h post application
Doses / concentrations
Remarks:
Doses / Concentrations:
males: 31.6 mg/kg bw., females 21.5 mg/kg bw. (maximum tolerated dose as determined in a prexperiment)
Basis:
nominal conc.
No. of animals per sex per dose:
12
Evaluation: 5
Control animals:
other: physiological saline solution (0.9 %)
Positive control(s):
- cyclophosphamide
- Route of administration: oral (gavage)
- Doses / concentrations: 31.6 mg/kg bw

Examinations

Tissues and cell types examined:
bone marrow smear of the femurs
From each animal 1000 PCEs were scored.
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION:
highest tolerable dose (higher concentrations caused severe toxic symptoms)

METHOD OF ANALYSIS:
scoring under microscope

Evaluation criteria:
test substance is considered mutagenic if it produces a statistically significant (p< 0.05) and reproducible positive response at any of the test points compared to the negative control group
Statistics:
Poisson test

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
hypokinesiahypokinesia, tremor, clonic convulsions (females only), decreased muscle tone, loss of righting reflexes. One female animal died.

RESULTS OF RANGE-FINDING STUDY
- Dose range: 31.6 - 38.3 mg/kg bw (males), 21.5-31.6 mg/kg bw (females)
- Solubility: yes
- Clinical signs of toxicity in test animals: severe toxicity symptoms, one female of the high dose died.
- Evidence of cytotoxicity in tissue analyzed: no
- Rationale for exposure: methodical reasons


RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no
- Ratio of PCE/NCE (for Micronucleus assay): slightly lower in the test group, no clear myelotoxic effect can be deduced from the findings
control: 2.8/1.6 (24 h), 1.6/3.0 (48 h) ACA: 2.0/1.4 (24 h), 2.0/0 (48 h), values are presented as males/females

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
No significant test material related increase in micronucleated PCEs was observed. Therefore the substance is considered non mutagenic in the mouse micronucleus assay.