Xanthylium, 3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethyl-, molybdatesilicate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 April 2018 - 20 April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

29 July 2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

31 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

d.d. 22 january 2018

Test material

Test material information

1

Reference substance name:

Xanthylium, 3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethyl-, molybdatesilicate

EC Number:

278-270-6

EC Name:

Xanthylium, 3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethyl-, molybdatesilicate

Cas Number:

75627-12-2

Molecular formula:

C54H58N4O6.MoO4 + C54H58N4O6.SiO3

IUPAC Name:

3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethyl-10λ⁴-xanthen-10-ylium dioxomolybdenumbis(olate) silicate

Test material form:

solid: particulate/powder

Details on test material:

- Appearance: Pink powder
- Storage conditions: At room temperature

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

skin obtained from plastic surgery from multiple donors

Details on animal used as source of test system:

EpiDerm™ Reconstructed Human Epidermis (Lot no.: 28326)
- All cells used to produce Epiderm™ are purchased or derived from tissue obtained by MatTek Corporation from acredited institutions.
- Cells are screened for potential biological contaminants (HIV-1, Hepatitis B, Hepatitis C, bacteria, yeast and fungi)

Justification for test system used:

Recommended test system in international guidelines (OECD and EC).

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm Skin Model (EPI-200)
- Tissue lot number: 28326, kit G and H
- Surface: 0.6 cm^2
- The model consists of keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis.

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: All incubations, with the exception of the test item incubation of 3 minutes at room temperature, were carried out in a controlled environment at 37.0 ± 1.0°C (actual range 35.7 - 37.2°C).

REMOVAL OF TEST MATERIAL AND CONTROLS
- After the exposure period, the tissues were washed with phosphate buffered saline to remove residual test item.
- Due to the characteristics of the test item it was difficult to remove and therefore some residual test item could still be left on the skin.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h
- Spectrophotometer: TECAN Infinite® M200 Pro Plate Reader
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 2 replicates per exposure duration, one negative control, one positive contol.

ACCEPTANCE OF RESULTS:
The in vitro skin corrosion test is considered acceptable if it meets the following criteria:
a) The absolute mean OD570 of the two tissues of the negative control should reasonably be within the laboratory historical control data range.
b) The mean relative tissue viability following 1-hour exposure to the positive control should be <15 %.
c) In the range 20 - 100% viability, the Coefficient of Variation (CV) between tissue replicates should be ≤ 30%.

DECISION CRITERIA
A test item is considered corrosive in the skin corrosion test if:
a) The relative mean tissue viability obtained after 3-minute treatment compared to the negative control tissues is decreased below 50%.
b) In addition, a test item considered non-corrosive (viability ≥ 50%) after the 3-minute treatment is considered corrosive if the relative tissue viability after 1-hour treatment with the test item is decreased below 15%.

A test item is considered non corrosive in the in vitro skin corrosion test if:
a) The relative mean tissue viability obtained after the 3-minute treatment compared to the negative control tissues is not decreased below 50%.
b) In addition, the relative tissue viability after the 1-hour treatment is not decreased below 15%.

DATA INTERPRETATION
See Table 1 (Any other information on methods inc. tables)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
Amount applied: 23.85 to 36.08 mg was applied to skin moistened with 25 μL Milli-Q water

Duration of treatment / exposure:

3-minute and 1-hour

Number of replicates:

2 replicates per exposure duration (4 in total), one negative control, one positive control.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3-minute exposure

Value:

98

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100

Positive controls validity:

valid

Remarks:

14

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1-Hour exposure

Value:

93

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100

Positive controls validity:

valid

Remarks:

6.8

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: No
- Colour interference with MTT: No

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes, mean relative tissue viability following 1-hour exposure was 6.8%.
- Acceptance criteria met for variability between replicate measurements: Yes

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

An in vitro skin corrosion test was conducted according to OECD guideline 431 and GLP principles. Based on the results, C.I. Pigment Red 81:2 is concluded not to be corrosive in the in vitro skin corrosion test and therefore is not classified for corrosive effects on the skin according to according to GHS and CLP criteria.