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Toxicological information

Genetic toxicity: in vitro

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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:
20 March 2013 to 3 April 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

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

Method

Target gene:
his
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Metabolic activation system:
S9 mix
Test concentrations with justification for top dose:
5, 15, 50, 150, 500, 1500 and 5000 µg/plate of hydroxyprednisolone he tests on S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: hydroxyprednisolone was insoluble in water but soluble in DMSO
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
2-nitrofluorene
sodium azide
benzo(a)pyrene
other: 2-Aminoanthracene
Details on test system and experimental conditions:
Two independent mutation tests were performed in the presence and absence of liver preparations (S9 mix) from rats treated with phenobarbital and 5,6-benzoflavone. The first test was a standard plate incorporation assay; the second included a pre-incubation stage.

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
It was concluded that 16alpha-hydroxyprednisolone showed no evidence of mutagenic activity in this bacterial system at doses up to 5000 micrograms/plate under the test conditions employed.