N-[(1R)-2-[(Methylsulfonyl)oxy]-1-phenylethyl]carbamic acid 1,1-dimethylethyl 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:

24 September - 28 September 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl N-[(1R)-2-(methanesulfonyloxy)-1-phenylethyl]carbamate

EC Number:

855-580-5

Cas Number:

102089-75-8

Molecular formula:

C14H21NO5S

IUPAC Name:

tert-butyl N-[(1R)-2-(methanesulfonyloxy)-1-phenylethyl]carbamate

Test material form:

solid: particulate/powder

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

other: human-derived epidermal keratinocytes

Cell source:

other: not specified

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Since the test article was solid, 25 µL of sterile CMF-DPBS was added to the tissue surface prior to the addition of the solid test article (which was added using a 25 mg dosing spoon). The test article was mixed on the surface of the tissues using a sterile glass rod.

Duration of treatment / exposure:

The test article, the positive control (5% Sodium Dodecyl Sulfate (SDS)), and the negative control (Calcium & Magnesium Free-Dulbecco’s Phosphate Buffered Saline (CMF-DPBS)), were treated in triplicate EpiDermTM tissues for a 60±1 minute exposure period. After the 60±1 minute exposure period, the tissues were rinsed with sterile CMF-DPBS, filling and emptying the cell culture insert approximately 15 times to remove any residual test article. A stream of CMF-DPBS was directed onto the tissue surface to assure removal of the test or control article.

Duration of post-treatment incubation (if applicable):

The treatment was followed by a 42-hour postexpsoure expression period.

Number of replicates:

Triplicate

Test system

Details on study design:

Since the test article was a solid, it was not evaluated in the mesh compatibility test.
The test article was not observed to directly reduce MTT in the absence of viable cells.
The test article was not considered to have probable photometric MTT interference.

The experimental design of the study consists of the determination of the direct MTT reduction potential, assessment of colorant potential, a pH determination of the neat liquid test article and/or dosing dilution, if possible, and a definitive Skin Irritation Test (SIT). On the day of receipt, the EpiDerm(TM) tissues are conditioned by an overnight incubation for release of transport-stress related compounds and debris. After pre-incubation, tissues are topically exposed in triplicate to the test article, positive control, and negative control for 60 minutes. Tissues are then thorougly rinsed to remove the test or control article, blotted, and transferred to fresh medium. After a 24 hour incubation period, the tissues are refed with fresh medium, and incubated for another 18 hours for a total 42-hour post-exposure incubation period. Viability will be determined by the NAD(P)H-dependent microsomal enzyme redution of MTT in control and test article-treated tissues. The MTT assay is performed by transferring the tissues to 24-well plates containing MTT medium (1 mg/mL). Ater a 3-hour MTT incubation, the blue formazan salt formed by cellular mitochondria is extracted with 2 mL isopropanol per tissue and the optical density of the extracted formazan is determined with a spectrophotometer at 570 nm. Relative cell viability is calculated for each tissue as % of the mean of the netative control-treated tissues.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Value:

104.7

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

The mean tissue viability of the positive control was 5%.

Any other information on results incl. tables

The assay was accepted when the following criteria were met: 1) the positive control (5% SDS) resulted in a mean tissue viability <= 20%, 2) the mean OD570 value of the negative control tissues was >= 0.8 and < 2.8, and 3) the standard deviations of the positive and negative control calculated from individual percent tissue viabilities of the three identically treated replicates were < 18%.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

According to the prediction model presented in OECD Guideline 439, the test article was predicted to be a non-irritant.