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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: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study report, only one dose tested

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
yes
Remarks:
see principles
Principles of method if other than guideline:
one dose used (100 mg/kg)
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
LAB 870 (Beta-Cyclodextrin)
batch 392344

Test animals

Species:
mouse
Strain:
other: I.O.P.S., OFl (IFFA CREDO)
Sex:
male/female
Details on test animals and environmental conditions:
The animals (6 - 8 weeks old mouse) were housed in groups of 2 (prelimi-nary study) or 5 (final study) in plastic cages (dimensions: 205 x 118 x 127 mm) on a dust free litter. The temperature was kept at 22 + 3 °C. The rela-tive air humidity was 30 - 70 %, with air changes of at least 8 per hour; arti-ficial lighting : 12 hours out of 24.
Commercial pelleted rat-mouse A04 CR diet - batch 70.630 (U.A.R. - Usine d'Alimentation Rationelle, Villemoisson sur Orge, France). Each manufac-turing batch was analysed to detect contaminants. Drinking water ad libitum.

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
carboxymethylcellulose hydrogel (1%)
Details on exposure:
one injection of 10 ml/kg
Duration of treatment / exposure:
24, 48, and 72 hours respectively
Frequency of treatment:
once
Post exposure period:
24, 48, and 72 hours respectively
Doses / concentrations
Remarks:
Doses / Concentrations:
100 mg/kg bw
Basis:
nominal conc.
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide
- Justification for choice of positive control(s):
- Route of administration:
- Doses / concentrations:

Examinations

Tissues and cell types examined:
erythrocytes from the femur bone marrow
Details of tissue and slide preparation:
The animals were killed at the end of the treatment period by dislocation of the cervical vertebrae. The bone marrow removed from both femurs was suspended in foetal calf serum and centrifugated. For each animal, two smears were prepared on slides stained with May-Grunwald-Giemsa.
For each animal 1000 polychromatic erythrocytes were examined. A count of the number of polychromatophile erythrocytes bearing micronuclei was performed. At the same time, an observation and a count of the number of normochromatophile erythrocytes were carried out.
The results are expressed for each animal by the following ratio : number of normochromatophile erythrocytes for 400 polychromatophile erythrocytes. The average test and standard deviation were calculated for each group. The results are reported in the appendix.
Evaluation criteria:
not reported
Statistics:
The results are expressed as the number of cells bearing micronuclei for 1000 polychromatophile erythrocytes observed.
A statistical analysis wi th the aid of Student's test and the test of exact bilateral comparison were performed.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: 100- 5000 mg/kg bw (intraperitoneal)
- Solubility: in vehicle soluble
- Clinical signs of toxicity in test animals: The results of the preliminary study show that the highest dose tolerated under the experimental conditions employed, averages 100 mg/kg. Therefore, the 100 mg/kg doses was chosen for the final trial.
- Evidence of cytotoxicity in tissue analyzed:
- Rationale for exposure: toxicity reasons, high mortality in higher concentrations
- Harvest times: 24, 48 and 72 h


RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no
- Ratio of PCE/NCE (for Micronucleus assay): NCE/PCE 1.32 for 24 h harvest time, 0.82 (48 h) and 0.67 (72 h)
:

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Substance is not mutagenic in the in vivo micronucleus assay under the conditions used
Executive summary:

The mutagenic potential of the test article beta-Cyclodextrin (purity not specified) was tested in the I.O.P.S., OFl (IFFA CREDO) mouse using the micronucleus test, at a preliminarily defined dose of 100mg/kg according to a procedure similar to OECD 474.

The animals (5 males and 5 females per group) were administered the product by the intraperitoneal route (vehicle 1% carboxymethylcellulose hydrogel) and killed 24, 48 or 72 hours after administration. For each animal an examination of 1000 polychromatic erythrocytes obtained from the femoral bone marrow was performed. The statistical analysis of the results does not show any significant increase in the number of polychromatic erythrocytes bearing micronuclei in the animals treated with the test substance. The results obtained with the positive control (cyclophosphamide) are significantly positive. Concerning the ratio normochromatic/polychromatic erythrocytes which in the absence of toxical effect is close to 1, there was no significant increase in this value in the animals treated with the test article. A significant increase was observed in the animals treated with the positive control. To conclude, the test article did not induce any mutagenic effect in the mouse when administered at a dose of 100 mg/kg.