1H-Benz[e]indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonate (1:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test accoding to GLP and the study procedures described in this report were based on the most recent OECD and EC guidelines.

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 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,1,2,3-tetramethyl-1H-benzo[e]indol-3-ium 4-methylbenzene-1-sulfonate

Cas Number:

141914-99-0

Molecular formula:

C23H25NO3S

IUPAC Name:

1,1,2,3-tetramethyl-1H-benzo[e]indol-3-ium 4-methylbenzene-1-sulfonate

Details on test material:

Identification: V173520
Appearance: White powder (determined by WIL Research Europe)
Batch: AN
Purity/Composition: Not indicated
Test substance storage: At room temperature
Stable under storage conditions until: 20 April 2017 (expiry date)

Purity/composition correction factor: No correction factor required
Test substance handling: No specific handling conditions required
Stability at higher temperatures: Yes, maximum temperature: 50°C(drying), maximum duration: 24 h
Chemical name (IUPAC), synonym or trade name: 1,1,2,2-tetramethyl-1H-Benz(e)indolium 4- methylbenzenesulfonate
CAS Number: 141914-99-0
Molecular formula: C23H25NO3S
Molecular weight: 395.53

Test animals

Species:

other: EpiDerm Skin Model

Strain:

other: Not applicable

Test system

Type of coverage:

other: Topical application

Preparation of test site:

other: Not applicable

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

30.1 - 32.9 mg solid test medium

Duration of treatment / exposure:

3 minutes and 1 hour

Details on study design:

The skin tissues were kept in the refrigerator the day they were received. The next day, at least 1 hour before the assay is started the tissues were transferred to 6-well plates containing 0.9 ml DMEM medium per well. The level of the DMEM medium is just beneath the tissue (see fig 1). The plates were incubated for approximately 1 hour at 37.0 ± 1.0oC. The medium was replaced with fresh DMEM medium just before V173520 was applied. The test was performed on a total of 4 tissues per test substance together with a negative control and positive control. Two tissues were used for a 3-minute exposure to V173520 and two for a 1-hour exposure. The skin was moistened with 25 μl Milli-Q water (Millipore Corp., Bedford, Mass., USA) to ensure close contact of the test substance to the tissue and 30.1 to 32.9 mg of the solid test substance (with a glass weight boat) was added into the 6-well plates on top of the skin tissues. The remaining tissues were treated with 50 μl Milli-Q water (negative control) and with 50 μl 8N KOH (positive control), respectively. In addition for the 3 minute and 1 hour exposure two freeze-killed tissues treated with test substance and two freeze-killed negative control treated tissues were used for the cytotoxicity evaluation with MTT. After the exposure period, the tissues were washed with phosphate buffered saline (Invitrogen Corporation, Breda, The Netherlands) to remove residual test substance. Rinsed tissues were kept in 24 well plates on 300 μl DMEM medium until 6 tissues (= one application time) were dosed and rinsed.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: remaining cell viability after exposure

Basis:

mean

Time point:

other: 3 minutes

Score:

100

Remarks on result:

other: The relative mean tissue viability obtained after 3-minute treatment with V173520 compared to the negative control tissues was 100%

Results 2

Irritation parameter:

other: remaining cell viability after exposure

Basis:

mean

Time point:

other: 1 hour

Score:

157

Remarks on result:

other: The relative mean tissue viability obtained after 1-hour treatment with V173520 compared to the negative control tissues was 157%

Applicant's summary and conclusion

Conclusions:

Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with V173520 compared to the negative control tissues was 100% and 157%, respectively. Because the mean relative tissue viability for V173520 was not below 50% after the 3-minute treatment and not below 15% after the 1-hour treatment V173520 is considered to be not corrosive.