Octadecanoic acid, reaction products with triethylenetetramine, chloromethane-quaternized

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Test material

Test material information

1

Reference substance name:

Octadecanoic acid, reaction products with triethylenetetramine, chloromethane-quaternized

EC Number:

291-716-4

EC Name:

Octadecanoic acid, reaction products with triethylenetetramine, chloromethane-quaternized

Cas Number:

90459-71-5

Molecular formula:

Not applicable - UVCB substance

IUPAC Name:

Octadecanoic acid, reaction products with triethylenetetramine, chloromethane-quaternized

Test material form:

solid

In chemico test system

Details on the study design:

The in chemico direct peptide reactivity assay (DPRA) enables detection of the sensitising potential of a test item by quantifying the reactivity of test chemicals towards synthetic peptides containing either lysine or cysteine.

In the present study Octadecanoic acid, reaction product with triethylenetetramine, chloromethane-quaternized was dissolved in methanol, based on the results of the pre-experiments. Since no molecular weight could be derived the test item was tested to its maximum solubility, which was 45 mg/mL. The test item solutions were tested by incubating the samples with the peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC analysis.

For the 45 mg/mL stock solution of the test item precipitation was observed when diluted with the cysteine peptide solution. After the 24 h ± 2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. Precipitation was observed for the samples of the test item (including the co-elution control). Samples were centrifuged prior to the HPLC analysis.

For the 45 mg/mL stock solution of the test item precipitation was observed when diluted with the lysine peptide solution. After the 24 h ± 2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. Precipitation was observed for the samples of the test item (including the co-elution control). Samples were centrifuged prior to the HPLC analysis. Phase separation was observed for the samples of the positive control (including the co-elution control). Samples were not centrifuged prior to the HPLC analysis.
Since the acceptance criteria for the depletion range of the positive control were fulfilled, the observed phase separation was regarded as not relevant.

Results and discussion

Positive control results:

Cinnamic aldehyde ((2E)-3-phenylprop-2-enal)

In vitro / in chemico

Results

Key result

Run / experiment:

other: HPLC determination of adducts between lysine-peptides and cisteine-peptides with the test substance.

Parameter:

other: Percentage depletion of peptides

Value:

0.31

Positive controls validity:

valid

Remarks on result:

not determinable

Remarks:

The solubility of the test substance was assayed with different solvents: - acetonitrile - dist. water - dist. water : acetonitrile 1:1 (v/v) - isopropanol - methanol - 1,4-butanediol - N,N-dimethylformamide - ethanol - tert. butanol The test item was not soluble at the highest concentration (100 mg/mL) in any of the tested solvents. However, as methanol seemed to be the best suited solvent tested, the concentration was lowered stepwise. At a concentration of 45 mg/mL the test item was completely soluble in methanol, therefore, methanol was chosen as suitable vehicle for the main experiments. The stock solution of the test item showed minimal reactivity towards the synthetic peptides. The mean depletion of both peptides was ≤ 6.38% (0.31%). Since precipitation was observed, the full contact of peptide and test item is not guaranteed. According to the evaluation criteria in the guideline, no firm conclusion on the lack of reactivity should be drawn from a negative result, if a test chemical is tested in concentration < 100 mM. Therefore, no prediction can be made.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

In this study under the given conditions the test item showed minimal reactivity towards both peptides. Due to the observed precipitation and the unknown concentration of the test item the prediction model does not apply and a prediction cannot be made.