Methyl 12-hydroxyoctadecanoate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Guideline study under GLP

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

Version / remarks:

In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method, 28 July 2015.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

“In vitro Skin Irritation: Reconstructed Human Epidermis Test Method”. 06-Jul-2012.

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: In Vitro EpiDermTM Skin Irritation Test (EPI-200-SIT) For use with MatTek Corporation’s Reconstructed Human Epidermal Model EpiDerm (EPI-200-SIT)

Version / remarks:

07-Nov-2014

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Methyl 12-hydroxyoctadecanoate

EC Number:

205-471-8

EC Name:

Methyl 12-hydroxyoctadecanoate

Cas Number:

141-23-1

Molecular formula:

C19H38O3

IUPAC Name:

methyl 12-hydroxyoctadecanoate

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Vertellus, 0000140430

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: assumed to be stable for duration of study

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Not specified

Justification for test system used:

This test uses the EpiDerm™ reconstructed human epidermis model (MatTek) which consists of normal human epidermal keratinocytes (NHEK) and therefore represents in vitro the target organ of the species of interest and closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e. the epidermis.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm™-Standard Model (EPI-200™), a reconstituted three-dimensional human epidermis model
- Tissue batch number(s): Lot No.: 25883
- Date of initiation of testing: 20 February 2018

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 ± 1 °C, followed by room temperature laminar flow
- Temperature of post-treatment incubation (if applicable): 37 ± 1 °C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: 15 1mL DPBS washes, followed by 3 submersions in 150 mL DPBS
- Observable damage in the tissue due to washing: None
- Modifications to validated SOP:

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 5 mg/mL MTT diluted in DMEM to a final concentration of 1 mg/mL
- Incubation time: 3 hr
- Spectrophotometer: Standard plate spectrophotometer
- Wavelength: 570 nM
- Filter: yes
- Filter bandwidth: band pass of maximum ± 30 nm
- Linear OD range of spectrophotometer: Not reported

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: 4.3%
- Morphology and Reproducibility: The EpiDerm (TM) epidermis model exhibits in vivo-like morphological and growth characteristics which are uniform and highly reproducible. It consists of organised basal, spinous and granular layers and a multi-layered stratum corneum analogous to patterns found in vivo.
- Contamination: None

NUMBER OF REPLICATE TISSUES: 3

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE : The mixture of 25 mg test item per 1 mL MTT medium showed no reduction of MTT compared to the solvent. The mixture did not turn blue/purple. Therefore, NSMTT equalled 0%.
The mixture of 25 mg of the test item per 300 µl aqua dest. and/or per 300 µL isopropanol showed no colouring detectable by unaided eye-assessment. Therefore, NSC equalled 0%.

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 3 per condition (vehicle control, positive control, test item)

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the tissue viability after exposure and post-incubation is less than or equal to 50%. Further testing is required to resolve between UN GHS categories 1 and 2 and decide on the final classification of the test substance. The test substance may be considered as non-irritant to skin in accordance with UN GHS “No Category” if the tissue viability after exposure and post-treatment incubation is more than 50%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 µL of sterile DPBS were applied to the epidermal surface in order to improve the contact between the powder and the epidermis. Afterwards, 25 mg (39 mg/cm^2) of the test item were applied directly atop the EpiDerm TM tissue using an application spoon, avoiding compression of the test item. The test item was spread to match size of the tissue by using a bulb-headed Pasteur pipette.

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL
- Concentration (if solution): 5%

Duration of treatment / exposure:

60 min

Duration of post-treatment incubation (if applicable):

42 h

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Negative Control

Value:

100

Vehicle controls validity:

not applicable

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive Control

Value:

3.7

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

not applicable

Remarks on result:

positive indication of irritation

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Test Item

Value:

88.9

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance was evaluated for skin irritation potential by assessing its effect on a reconstituted three-dimensional human epidermis model (OECD 439, EpiDerm(TM)) using MTT reduction as an indication of tissue viability. The test substance was observed to be non-irritating at doses up to 25 mg/plate.