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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Comparable to OECD Guideline Study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
.beta.-Cyclodextrin, 2-hydroxypropyl cycloheptaamylose
IUPAC Name:
.beta.-Cyclodextrin, 2-hydroxypropyl cycloheptaamylose
Constituent 2
Chemical structure
Reference substance name:
-
EC Number:
420-920-1
EC Name:
-
Cas Number:
128446-35-5
Molecular formula:
Hill formula: (C42H70-nO35)(C3H7O)n; n(mittel)=5,25
IUPAC Name:
2-Hydroxypropyl-.beta.-cyclodextrine ethers
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report): hydroxypropylated .beta.-cyclodextrin
- Physical state: white powder
- Analytical purity: 89.16%
- Lot/batch No.: DRD#SSBTS-96.001
- Test Article Receipt: 03/08/96
- Study Initiation: 04/02/96
- Storage condition of test material: room temperature; protected from exposure to light and moisture

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Species / strain / cell type:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
Positive control (µg/plate): 1.0 (All Salmonella Strains), 10 (WP2 uvrA), 100 (WP2)
Positive control (µg/plate): 1.0 (TA98, TA1538), 1.0 (TA100, TA 1535), 75 (TA1537), 1,000 (Both E.coli Strains)
Vehicle (µg/plate): 6.5, 9.7, 32, 65, 97, 324, 648, 972, 3239, 4859

97mg/ml for 5mg/plate
Vehicle / solvent:
- Solvent used: water
- Justification for choice of solvent: compatibility with the target cells

Test article was soluble in water at approximately 97 mg/ml, the maximum concentration tested.
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other:
Remarks:
2-aminoanthracene; All Salmonella Strains and WP2 uvrA (pKM101)
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other:
Remarks:
sterigmatocystin; WP2 (pKM101)
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA98, TA1538
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA100, TA1535
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA1537
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
Both E.coli Strains
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation
DURATION
- Preincubation period:
- Exposure duration:
- Expression time (cells in growth medium):
- Selection time (if incubation with a selection agent):
- Fixation time (start of exposure up to fixation or harvest of cells):

SELECTION AGENT (mutation assays):
SPINDLE INHIBITOR (cytogenetic assays):
STAIN (for cytogenetic assays):

NUMBER OF REPLICATIONS:

NUMBER OF CELLS EVALUATED:

DETERMINATION OF CYTOTOXICITY
- Method: other: dissecting microscope

OTHER EXAMINATIONS:
- Determination of polyploidy:
- Determination of endoreplication:
- Other:

OTHER:
Evaluation criteria:
For the test article to be evaluated positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain with a minimum of two increasing concentrations of test article. Data sets for strains TA1535, TA1537 and TA1538 were judged positive if the increase in mean revertants at the peak of the dose response is equal to or greater than three times the mean vehicle control value. Data sets for strains TA98, TA100 and WP2 uvrA (pKM101) and WP2 (pKM101) were judged positive if the increase in mean revertants at the peak of the dose response is equal to or greater than two times the mean vehicle control value.

Results and discussion

Test resultsopen allclose all
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
Vehicle controls validity:
not applicable
Untreated negative controls validity:
not valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not applicable
Untreated negative controls validity:
not valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: none
- Effects of osmolality: none
- Evaporation from medium: no
- Water solubility: Yes at approximately 97 mg/ml
- Precipitation:
- Other confounding effects: not applicable

RANGE-FINDING/SCREENING STUDIES: Yes

COMPARISON WITH HISTORICAL CONTROL DATA: Yes

ADDITIONAL INFORMATION ON CYTOTOXICITY:
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

Under the conditions of this study, test article hydroxypropylated .beta.-cyclodextrin was concluded to be negative in the Salmonella/Mammalian Microsome (Ames Test) and Esclzericlzia coli WP2 Mutagenesis Assay.
Executive summary:

The test article, hydroxypropylated .beta.-cyclodextrin, was tested according to OECD Guideline 471 in the bacterial reverse mutation assay using S.typhimurium tester strains TA98, TA100, TA1535, TAl537 and TA1538 and E. coli tester strains WP2uvrA(pKM101) and WP2 (pKM101) in the presence and absence of Aroclor-induced rat liver S9. The assay was performed in two phases, using the plate incorporation and preincubation methods. The first phase, the dose range-finding study, was used to establish the dose range for the mutagenicity assay. The second phase, themutagenicity assay (initial and confirmatory assays), was used toevaluate the mutagenic potential of the test article. The preincubation method was used only for the confirmatory assay. The dosing solutions were adjusted to compensate for the purity of the test article.

Water was selected as the solvent of choice based on compatibility with the target cells. The test article was soluble in water at approximately 97 mg/ml, the maximum concentration tested.

In the preliminary toxicity assay, the maximum dose tested was 5 mg per plate; this dose was achieved using a concentration of 97 mg/ml and a 50 µl plating aliquot. Neither precipitate nor appreciable toxicity was observed. Based on the findings of the toxicity assay, the maximum dose plated in the mutagenicity assay was 5 mg per plate.

In the mutagenicity assay, no positive response was observed. Neither precipitate nor appreciable toxicity was observed.

Under the conditions of this study, test article hydroxypropylated .beta.-cyclodextrin was concluded to be negative in the Salmonella/Mammalian Microsome (Ames Test) and Esclzericlzia coli WP2 Mutagenesis Assay.