Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
26 June to 29 June 2001
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: TOX-GEN-MUT-005
Version / remarks:
Internal Eli lilly procedure
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Method

Target gene:
S9 fraction prepared from the livers of Aroclor 1254-induced rats.
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Test concentrations with justification for top dose:
Concentrations for 312.5, 625, 1250, 2500 and 5000ug/plate were selected based on the result of a preliminary range-finding assay
Vehicle / solvent:
DMSO
Controls
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
N-ethyl-N-nitro-N-nitrosoguanidine
Details on test system and experimental conditions:
Agar plates are prepared prior to study initiation and maintained at room temperature for approximately 1 week or refrigerated for up to 1 month until sued. Test concentrations used in the mutagenicity assay were selected based on a preliminary range-finding assay of the test article with S. typhimurium strains TA98, TA100, TA1535, TA1537 and Esxherichia coli WP2uvrA. Test concentrations selected for this study are listed in the Doser Level Seciton. On the day prior to study initiation, a cultre of each baterial strain is inoculated and incubated overnight. Top agar is prepared prior to study iniiation. Just prior to plate incorporation, an S9 mix is prepared for metabolic activiation and is maintained on ice throughout the plating procedure.
Evaluation criteria:
The vehicle control (DMSO, water or other appropriate vehicle control) must show a normal range of bacterial colonies for each baterial strain and should be consistent with historical data. The positive controls (MNNG, 2NF, 9AmAc and 2AA) must show a mutagenic response and should be consistent with historical data. In the absence of toxicity or precipitation, a maximum treatment concentration of 5000ug/plate is considered sufficient high to support study validity.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
True negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
True negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
True negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
True negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
True negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no mutagenic potential (based on QSAR/QSPR prediction)

Applicant's summary and conclusion

Conclusions:
The substance was not mutagenic without or with metabolic activation in the Ames S.typhimurium/E. coli bacterial mutation assay.