Imidodicarbonic acid, 2-[5-bromo-3-[[(4-methylphenyl)sulfonyl]oxy]-2-pyridinyl]-, 1,3-bis(1,1-dimethylethyl) ester

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 January 2016 to 29 January 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

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:

Organisation for Economic Co-operation and Development (OECD), OECD Guidelines for Testing of Chemicals, Guideline no. 431: In Vitro Skin Corrosion: reconstructed human epidermis (RHE) test method (adopted 28 July 2015).

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

European Community (EC). Commission regulation (EC) No. 440/2008, Part B: Methods for the Determination of Toxicity and other health effects, Guideline B.40 BIS: "In Vitro Skin Corrosion: Human Skin Model Test". Official Journal of the European Union No. L142, 31 May 2008.

Deviations:

no

GLP compliance:

yes

Remarks:

Exception: The characterisation of the test item was conducted in a pre-GIP environment.

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl N-{5-bromo-3-[(4-methylbenzenesulfonyl)oxy]pyridin-2-yl}-N-[(tert-butoxy)carbonyl]carbamate

EC Number:

810-844-9

Cas Number:

1803573-21-8

Molecular formula:

C22H27BrN2O7S

IUPAC Name:

tert-butyl N-{5-bromo-3-[(4-methylbenzenesulfonyl)oxy]pyridin-2-yl}-N-[(tert-butoxy)carbonyl]carbamate

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Purity by HPLC, % a/a: 99.7

In vitro test system

Test system:

human skin model

Remarks:

EpiDerm Skin Model (EPI-200, Lot no.: 23297 kit M and N)

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from multiple donors

Details on animal used as source of test system:

Tissues
On the day of receipt the tissues were kept on agarose and stored in the refrigerator. On the next day, at least one hour before starting the assay the tissues were transferred to 6-well plates with 0.9 ml DMEM medium.

DMEM (Dulbecco’s Modified Eagle’s Medium)
Supplemented DMEM medium, serum-free supplied by MatTek Corporation.

MTT medium
MTT concentrate (5 mg/ml) diluted (1:5) with MTT diluent (supplemented DMEM). Both supplied by
MatTek Corporation.

Environmental conditions
All incubations, with the exception of the test item incubation of 3 minutes at room temperature, were carried out in a controlled environment, in which optimal conditions were a humid atmosphere of 80 - 100% (actual range 79 - 90%), containing 5.0 ± 0.5% CO2 in air in the dark at 37.0 ± 1.0°C (actual range 36.5 - 36.7°C). Temperature and humidity were continuously monitored throughout the experiment. The CO2 percentage was monitored once on each working day. Temporary deviations from the temperature, humidity and CO2 percentage may occur due to opening and closing of the incubator door. Based on laboratory historical data these deviations are considered not to affect the study integrity.

Justification for test system used:

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

Vehicle:

water

Remarks:

The skin was moistened with 25 μl Milli-Q water (Millipore Corp., Bedford, Mass., USA) to ensure close contact of the test item to the tissue

Details on test system:

The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm2) were cultured on polycarbonate membranes of 10 mm cell culture inserts.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

yes, concurrent MTT non-specific colour control

Amount/concentration applied:

30.5 to 35.0 mg of the solid test item was added into the 6-well plates on top of the skin tissues

Duration of treatment / exposure:

The test was performed on a total of 4 tissues per test item. Two tissues were used for a 3-minute exposure to PF-06841215 and two for a 1-hour exposure.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3-minute application

Value:

84

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1-hour application

Value:

81

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Any other information on results incl. tables

Table 3 Mean tissue viability in the in vitro skin corrosion test with PF-06841215

	3-minute application viability (percentage of control)	1-hour application viability (percentage of control)
Negative control	100	100
PF-06841215	84	81
Positive control	11	9

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Because the mean relative tissue viability for PF-06841215 was not below 50% after 3 minutes treatment and not below 15% after 1 hour treatment PF-06841215 is considered to be not corrosive.

Finally, it is concluded that this test is valid and that PF-06841215 is not corrosive in the in vitro skin
corrosion test under the experimental conditions described in this report.