Reaction products of 1,6-diisocyanatohexane, oligomers with 2-[(2-methacryloyl)oxy]ethyl 6-hydoxyhexanoate and 2-hydroxyethyl methacrylate

Genetic toxicity: in vitro

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:

21 Aug 2006 to 05 Dec 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 471) performed in compliance with USFDA GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 471 "Genetic Toxicology: Bacterial Reverse Mutation Test" (1998), ICH S2A document (1996), and ICH S2B document (1997).

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Type:

Constituent

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report: MTDID 8191
- Physical state: Clear, colorless, viscous liquid
- Analytical purity: 100%
- Lot/batch no.: FC03/167
- Expiration date of the lot/batch: Dec 2006
- Storage condition of test material: Ambient temperature in the dark
- Other: Stable during shelf life

Method

Species / strain

Species / strain / cell type:

other: S. typhimurium strains TA98, TA100, TA1535, and TA 1537 and E. coli strain WP2 uvrA

Additional strain / cell type characteristics:

other: Histidine dependent

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S9

Test concentrations with justification for top dose:

With S9-mix: 50, 150, 500, 1500, and 5000 ug per plate; Without S9-mix: 50, 150, 500, 1500, and 5000 ug per plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO (50 uL per 2 mL of top agar)
- Justification for choice of solvent/vehicle: Solubility of the test article and compatibilty with the test system.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene was used for all strains in the presence of metabolic activation. In the absence of metabolic activation, the following strain specific positive controls were used: TA98: 2-nitrofluorene, TA100 and TA1535: sodium azide, TA1537: 9-aminoa

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)
DURATION
- Exposure duration: 48 to 72 hours
SELECTION AGENT (mutation assays): 50 uM L-histidine in minimal top agar
DETERMINATION OF CYTOTOXICITY
- Method: Bacterial lawn was evaluated microscopically for evidence of cytotoxicity. A dose level is considered toxic if one or both of the following are met: 1) a >50% reduction in the mean number of revertants per plate as compared to the mean control value. This reduction must be accompanied by an abrupt dose-dependant drop in the revertant count. and/or 2) at least a moderate reduction in the background lawn.
OTHER: Plates that were not counted immediately at the end of exposure were stored at 2 to 8 C until colony counting could be conducted.

Evaluation criteria:

For a test article to be considered positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain over a minimum of two increasing concentrations of test article. Tester strains TA1535 and TA1537 were judged positive if the increase in mean revertants at the peak of the dose response was equal to or greater than 3.0-times the mean vehicle control value. Tester strains TA98, TA100, and WP2 uvrA were judged positive if the increase in mean revertants at the peak of the dose response was equal to or greater than 2.0-times the mean vehicle control value.

Statistics:

Mean and standard deviation of the number of revertants per plate were calculated

Results and discussion

Test results

Species / strain:

other: S. typhimurium strains TA98, TA100, TA1535, and TA 1537 and E. coli strain WP2 uvrA

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: 1500 and 5000 ug/plate
- Other confounding effects:
RANGE-FINDING/SCREENING STUDIES: In the initial rangefinding assay, the dose levels tested were 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 ug per plate. No positive mutagenic response was observed at any tested concentration. Precipitate was observed beginning at 1500 or at 5000 ug per plate. No appreciable toxicity was observed.
COMPARISON WITH HISTORICAL CONTROL DATA: The results of the positive controls and vehicle control were similar to the pooled historical control data from 2003 to 2005.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative Criteria used for interpretation of results:OECD GHS

Based on the results of this study, MTDID 8191 is not mutagenic in either the presence or absence of metabolic activation.

Executive summary:

OBJECTIVE: MTDID 8191 (Lot No. FC 03/167) was tested in the Bacterial Reverse Mutation Assay using Salmonella typhimurium tester strains TA98, TA100, TA1535 and TA1537 and Escherichia coli tester strain WP2 uvrA in either the presence or absence of Aroclor-induced rat liver S9.

METHODS: This study was compliant with USFDA GLP 21CFR58, USEPA GLP 40CFR160 and 40CFR792, UK GLP Compliance Programme, the Japan GLP standard and the OECD GLP. Analyses of the uniformity, concentration, and stability of the test article mixtures were not performed and were excluded from the compliance statement. This study was performed in accordance with ICH S2A (1996), ICH S2B (1997), and OECD 471 (1998). The assay was performed using the plate incorporation method. An initial study was performed to establish the dose range for the confirmatory mutagenicity assay and to provide a preliminary mutagenicity evaluation. The test article was dissolved in dimethyl sulfoxide (DMSO) to create a stock solution containing approximately 500 mg/mL. In the initial assay, the dose levels tested were 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 ug per plate. No positive mutagenic response was observed at any tested concentration. Precipitate was observed at 1500 and 5000 ug per plate. No appreciable toxicity was observed. Based on these findings, dose levels of 50, 150, 500, 1500 and 5000 ug per plate were tested in the confirmatory mutagenicity assay.

RESULTS: No positive mutagenic responses were observed in the first confirmatory assay with any of the tester strains in the presence of S9 activation or with tester strains TA98, TA100, TA1535 and TA1537 in the absence of S9 activation. Precipitate was observed at 1500 and 5000 ug per plate. No appreciable toxicity was observed. Due to a technical error, the E. coli tester strain WP2 uvrA was not tested with 1500 ug per plate in the absence of metabolic activation in the original confirmatory assay. A re-test was performed for WP2 uvrA with all dose levels in the absence of metabolic activation. No positive mutagenic response was observed in the re-test at dose levels of 50, 150, 500, 1500 or 5000 ug per plate. Precipitate was observed at 1500 and 5000 ug per plate. No appreciable toxicity was observed.

CONCLUSION: Based on the results of this study, MTDID 8191 was considered not mutagenic in either the presence or absence of metabolic activation.