2-ethyl-N-(3-methoxyphenyl)-N-methylbutanamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

The laboratory phase of the study was conducted from 7 March 2017 to 8 April 2017 at the Institute for In Vitro Sciences, Inc.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

February 2015

Deviations:

no

GLP compliance:

yes

Type of study:

direct peptide reactivity assay (DPRA)

Justification for non-LLNA method:

Non animal test method -OECD approved. The Direct Peptide Reactivity assay provides an in vitro procedure used for supporting the discrimination between skin sensitizers and non sensitizers in accordance with the UN GHS. According to REACH, In vivo methods can only be used if the in chemico or in vitro test methods are not adequate for the substance or cannot be used for classification and risk assessment

Test material

Test material information

Constituent 1

Reference substance name:

2-ethyl-N-(3-methoxyphenyl)-N-methylbutanamide

Cas Number:

2101947-22-0

Molecular formula:

C14H21NO2

IUPAC Name:

2-ethyl-N-(3-methoxyphenyl)-N-methylbutanamide

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
-Source and lot/batch No of test material: Sponsor Lot No. IA437-33
-Expiration date of the lot/batch: January 2019
Purity test date: 4 January 2017
Purity:98.5%
Appearance:clear light orange non-viscous liquid
Storage condition of test material:Room temperature

In chemico test system

Details on the study design:

The DPRA is an in chemico method which quantifies the remaining concentration of cysteine- or lysine-containing peptide following 24 hours incubation with the test chemical at 25+/- 2.5ºC. The synthetic peptides contain phenylalanine to aid in the detection. Relative peptide concentration is measured by highperformance liquid chromatography (HPLC) with gradient elution and UV detection at 220 nm. Cysteine and lysine peptide percent depletion values are then calculated and used in a prediction model which allows assigning the test chemical to one of four reactivity classes used to support the discrimination between sensitisers and non-sensitisers.

Results and discussion

Positive control results:

Cinnamic aldehyde % mean petide depletion for cysteine and lysine were 74.78% and 61.55% respectively.

In vitro / in chemico

Results

Key result

Run / experiment:

other: Single run

Parameter:

other: % peptide depletion of cysteine and lysine

Value:

0.16

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Any other information on results incl. tables

Prediction Model:

Mean Peptide Depletion of Cysteine and Lysine (%)		DPRA Prediction	Peptide Depletion of Cysteine (%)
0- 6.38	Minimal Reactivity	Negative	0- 13.89	Minimal Reactivity
6.39- 22.62	Low Reactivity	Positive	13.90- 23.09	Low Reactivity
22.63- 42.47	Moderate Reactivity		23.10- 98.24	Moderate Reactivity
42.48- 100	High Reactivity		98.25- 100	High Reactivity

DPRA Results

IIVS Test Article Number	Sponsor’s Designation	% Mean Peptide Depletion		% Mean Peptide Depletion of Cysteine and Lysine	Reactivity (Cysteine and Lysine)	Potential Sensitizer?
		Cysteine	Lysine
17AA10	FRET 15-0735	0.00	0.32	0.16	Minimal	No
Positive Control	Cinnamic Aldehyde	74.78	61.55

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Based on the results of the Direct Peptide Reactivity Assay for the test article, FRET 15-0735 (Lot# IA437 -33), was not predicted to be a potential skin sensitizer.

Executive summary:

The Direct Peptide Reactivity Assay was used to assess the skin sensitization potenetial of the test substance, FRET 15-0735 (Lot# IA437 -33).The skin sensitization potential of the test substance was evaluated by measuring the depletion of synthetic peptides containing either cysteine or lysine aminoacids following incubation with the test substance, using the protocol that is consistent with the OECD Test Guideline 442C “In ChemicoSkin Sensitization: Direct Peptide Reactivity Assay (DPRA)”[1]. Based upon the results of this study, the test substance, FRET 15-0735, was not classified as a skin sensitizer.

[1]           OECD Test Guideline 442C “In ChemicoSkin Sensitization: Direct Peptide Reactivity Assay (DPRA)”, Adopted 4 February 2015.