1,2-Pyrrolidinedicarboxylic acid, 4-oxo-, 1-(1,1-dimethylethyl) ester, (2S)-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 December 2019 - 17 January 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2019

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(2S)-1-(tert-butoxycarbonyl)-4-oxopyrrolidine-2-carboxylic acid

EC Number:

617-556-0

Cas Number:

84348-37-8

Molecular formula:

C10H15NO5

IUPAC Name:

(2S)-1-(tert-butoxycarbonyl)-4-oxopyrrolidine-2-carboxylic acid

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm™
- Tissue batch number(s): 30842
- Quality assurance date: 15.01.2020

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 ± 1.5°C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Volume and number of washing steps: several times

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 60 minutes
- Spectrophotometer: microplate reader (Versamax® Molecular Devices)
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues
- N. of replicates: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
The test item is identified as requiring classification and labelling according to UN GHS/ EU CLP “Category 2” or “Category 1”, if the tissue viability after exposure and post-incubation is less or equal to 50%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

25 mg (39.7 mg/cm2 according to guideline)

Duration of treatment / exposure:

60 minutes

Duration of post-treatment incubation (if applicable):

17 hours

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

main

Value:

95.08

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Treatment with the positive control induced a decrease in the viability compared with the negative control to 2.91%, thus ensuring the validity of the test system.
After treatment with the test item N-tert.-Butoxycarbonyl-4-oxo-L-proline the mean viability value was 95.08% compared to the relative absorbance value of the negative control. This value is above the threshold for irritancy of ≤ 50%. Therefore, the test item is not considered to possess an irritant potential.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, it can be stated that in this study and under the experimental conditions reported, N-tert.-Butoxycarbonyl-4-oxo-L-proline is non-irritant to skin according to UN GHS and EU CLP regulation.