alkyl substituted aryl diazo heterocyclic aryl ester

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 May 2015 to 29 June 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: compliant to GLP and testing guidelines, coherence between data, results and conclusion.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Test item: Disperse Red DYGJ 0702

Test animals

Details on test animals or test system and environmental conditions:

Test system: EPISKIN™ - 0.38 cm2
Supplier: SkinEthic Laboratories (4, A. Fleming – 69007 Lyon – France).
Batch numbers: 15-EKIN-025 (alive tissue) and 15-EKIN-020 (killed tissues)

Test system

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

20 mg/epidermis unit, each measuring 0.38 cm2 (treatment level: 53 mg/cm2).

Duration of treatment / exposure:

Exposure time of 15 ± 0.5 minutes. Test item treatment was carried out staggering samples of approximately 2 minutes while control treatments were staggered of 1 ± 0.5 minute.

Number of animals:

Number of replicates: 3

Details on study design:

Positive control item: Sodium Dodecyl Sulphate (SDS) (SIGMA, batch 041M8713V), diluted at the final concentration of 5% (v/v) in sterile water for injection (Baxter, batch 14C2403).

Negative control item: D-PBS (GIBCO, batch 1605086).

Non Specific Colour (NSC) control: test item treated tissues without MTT

Non SPecific MTT Reduction (NSMTT): killed tissues treated with the test item.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: mean relative variability

Value:

104.9

Remarks on result:

other:

In vivo

Irritant / corrosive response data:

The non specific colour (NSC), relative to the D-PBS Control, was 1.3%, lower than 5%. The non specific MTT reduction was 2.4% when performed with alive tissues.
Based on the results obtained ,only the OD-blank background subtraction was performed for the evaluation of irritant properties of Disperse Red DYGJ 0702.
The test item did not induce cell death in any replicate with a mean cell viability of 104.9%, when compared to the negative control.
Acceptable intra-replicate variability was obtained (SD of % variability lower than 18).

Any other information on results incl. tables

See Final Report.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

The test item Disperse Red DYGJ 0702 is classified as not irritant to the skin.

Executive summary:

The potential of the test item Disperse Red DYGJ 0702 to be irritant to the skin was investigated through an in vitro skin irritation study using a commercial reconstructed human epidermis (RhE) model named EPISKIN™. The experimental procedures are based on the OECD Guideline for testing of chemicals no. 439. The test item, as well as controls, were tested for their ability to impair cell viability after an exposure period of 15 minutes followed by a 42 ± 1 hour recovery period. The final endpoint of the assay is the colorimetric measurement of MTT reduction (blue formazan salt) in the test system being this reaction an index of cell viability. The test item was tested as supplied by the Sponsor.

Before the Main Assay, a preliminary test was carried out to evaluate the compatibility of the test item with the test system. In a first step, the test item was assayed for the ability of reducing MTT per se; a light brown/ reddish coloured suspension, with dark brown precipitate, was observed at the end of the incubation period, indicating that the test item could interact directly with MTT. In a second step, the test item was assayed for the ability of colouring water per se; a brown/reddish suspension was observed, which indicates a colouring capacity of the test item. Based on these results, additional controls were added in the Main Assay.

In the Main Assay, the test item was applied as supplied in three replicates at the treatment level of 20 mg/epidermis unit, each measuring 0.38 cm2 (treatment level: 53 mg/cm2). Positive and negative controls [a 5% (v/v) sodium dodecyl sulphate solution in water and Dulbecco’s phosphate buffered saline (D-PBS), respectively] were concurrently tested, in the same number of replicates and test conditions at the treatment level of 20 µL/epidermis unit. The negative control gave the expected baseline value (Optical Density values of the three replicates higher than 0.6) and variability [Standard Deviation (SD) of % viability lower or equal to 18], in agreement with the guideline indications. According to the method, the mean value is considered the baseline value of the experiment and thus represents 100% of cell viability. The positive control caused the expected cell death (2.8% of cell viability when compared to the negative control) and variability (SD of % viability equal to 0.1). Based on the stated criteria (mean viability ≤ 40\% and SD of % viability ≤ 18 ), the assay was regarded as valid.

In order to verify if the test item results had to be corrected, the non specific colour (NSC) was evaluated using one alive treated tissue without MTT staining and compared with the negative control. Moreover, non specific MTT reduction (NSMTT) was evaluated using killed tissues and compared with negative control performed with alive tissues. Based on the results obtained (NSC=1.3% and NSMTT=2.4%), only the OD-blank background subtraction was performed for the evaluation of irritant properties of Disperse Red DYGJ 0702. The test item did not induce cell death in any replicate with a mean cell viability of 104.9%, when compared to the negative control.

Based on the results obtained, the test item Disperse Red DYGJ 0702 is classified as not irritant to the skin.