[No public or meaningful name is available]

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 February 2018 - 12 March 2018

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Deviations were considered to have not affected the integrity or validity of the study.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Test material form:

semi-solid (amorphous): gel

In vitro test system

Test system:

isolated skin discs

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from multiple donors

Source strain:

other:

Justification for test system used:

System used to supplant in-vivo testing

Vehicle:

unchanged (no vehicle)

Details on test system:

Test System
EpiDerm™ Reconstructed Human Epidermis Model Kit

Supplier: MatTek
Date received: 22 February 2018
EpiDermTM Tissues (0.63cm2) lot number :25882
Assay Medium lot number:021518TMA
Upon receipt of the EpidermTM tissues, the sealed 24-well plate was stored in a refrigerator until use.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

50 uL

Duration of treatment / exposure:

3 min/60 min

Duration of post-treatment incubation (if applicable):

NA

Number of replicates:

2 ea. for postive and negative controls and substance at 3min, 60 min.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1/ @3 minutes

Value:

ca. 97.8

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

2/@ 60 min

Value:

ca. 111.8

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Predicted to be non-corrosive to the skin via employed test system. See attached background material.

Executive summary:

Introduction

The purpose of this test is to evaluate the corrosivity potential of the test item using the EpiDerm™ Human Skin Model after treatment periods of 3 and 60 minutes.

Corrosion is directly related to cytotoxicity in the EpiDerm™ tissue. Cytotoxicity is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. The results are used to make a prediction of the corrosivity potential of the test item.

Methods

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. Negative and positive control groups were treated for each exposure period. The test item was found to have the potential to cause color interference and therefore additional tissues were incorporated for color correction purposes. The test item was also found to directly reduce MTT and therefore, an additional procedure using freeze-killed tissues was performed. A third set of controls was included; comprising freeze-killed tissues, in order to prevent a double correction from a colored test item that also reduces MTT. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT-loading. After MTT loading each tissue was placed in 2 mL Isopropanol for MTT extraction.

At the end of the formazan extraction period each well was mixed thoroughly and triplicate 200 μL samples were transferred to the appropriate wells of a pre-labeled 96-well plate. The optical density (OD) was measured at 570 nm (OD570).

Data are presented in the form of percentage viability (MTT reduction in the test item treated tissues relative to negative control tissues). See attached background material.