Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
27 March to 14 April 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study in accordance with a recognised test method

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): PF-00346643
- Substance type: pure substance
- Physical state: pale yellow oil
- Analytical purity: 88.9%
- Lot/batch No.: 115565-67-1
- Expiration date of the lot/batch: 31 May 2008
- Stability under test conditions: stable
- Storage condition of test material: in a refrigerator (2-8°C)

Method

Target gene:
Histidine independence (Salmonella typhimurium)
Tryptophan independence (Escherichia coli)
Species / strainopen allclose all
Species / strain / cell type:
E. coli WP2 uvr A
Details on mammalian cell type (if applicable):
The Escherichia coli WPZuvrA strain detects base-pair substitutions. The strain lacks an excision repair system and is sensitive to agents such as UV. The sensitivity of the strain to a wide variety of mutagens has been enhanced by permeabilization of the strain using Tris-EDTA treatment. The strain was regularly checked to confirm the tryptophan-requirement, UV-sensitivity and the number of spontaneous revertants.
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell type (if applicable):
The Salmonella typhimurium strains were regularly checked to confirm their histidine-requirement, crystal violet sensitivity, ampicillin resistance (TA98 and TA100), UV-sensitivity and the number of spontaneous revertants.
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
3, 10, 33, 100, 333, 1000, 3330, 5000
Controls
Negative solvent / vehicle controls:
yes
Remarks:
dimethyl sulphoxide
Positive controls:
yes

Results and discussion

Test resultsopen allclose all
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Vehicle controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: strain/cell type:
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

In the dose range finding test, PF-00346643 was tested up to concentrations of 5000 µg/plate in the absence and presence of S9-mix in the strains TA100 and WP2uvrA. In tester strain TA100, toxicity was only observed at the dose level of 5000 µg/plate in the absence of S9-mix. In tester strain WP2uvrA, no toxicity was observed at any of the dose levels tested. Results of this dose range finding test were reported as part of the first experiment of the mutation assay.

PF-00346643 precipitated on the plates at dose levels of 3330 and 5000 µg/plate.

Based on the results of the dose range finding test, PF-00346643 was tested in the first mutation assay at a concentration range of 33 to 3330 pg/plate in the absence and presence of 5% (v/v) S9-mix in tester strains TAI 535, TA1 537 and TA98. Toxicity was only observed in the tester strains TAI 535 and TAI 537 in the absence of S9-mix.

In an independent repeat of the assay with additional parameters, PF-00346643 was tested at the same concentration range as the first assay in the absence and presence of 10% (v/v) S9-mix in tester strains TA1 535, TA1 537, TA98, TA1 00 and WP2uvrA. Toxicity was observed in the tester strains TAI 535 (absence and presence of S9-mix), TA98 and TA1 00 (absence of S9-mix).

PF-00346643 did not induce a significant dose-related increase in the number of revertant (His) colonies in each of the four tester strains (TAI 535, TA1 537, TA98 and TAI 00) and in the number of revertant (Trp+) colonies in tester strain WP2uvrA both in the absence and presence of S9-metabolic activation. These results were confirmed in an independently repeated experiment.

In this study, the negative and strain-specific positive control values were within our laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.

Refer to background information section for results tables.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Based on the results of this study it is concluded that PF-00346643 is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coil reverse mutation assay.