[No public or meaningful name is available]

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Stearic anhydride

EC Number:

211-318-6

EC Name:

Stearic anhydride

Cas Number:

638-08-4

Molecular formula:

C36H70O3

IUPAC Name:

octadecanoic anhydride

In vitro test system

Test system:

human skin model

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Duration of treatment / exposure:

One plate (3 tissues) was used as negative control; each tissue was treated with 30 µL DPBS buffer, a nylon mesh was added in order to ensure sufficient contact with the tis-sue surface.
One plate (3 tissues) was used as positive control; each tissue was treated with 30 µL 5% SDS-solution, a nylon mesh was added in order to ensure sufficient contact with the tis-sue surface.
One plate (3 tissues) was used for treatment with the test item:
The tissues were wetted with 25 µL DPBS buffer before applying the test item and spread-ing it to match the tissue size.
The following amounts were applied to the tissues:

Table 7.3 a Amounts of Test Item

Tissue Amount
1 25.2 mg
2 25.2 mg
3 25.8 mg

Tissues were dosed in 1-minute-intervals. After dosing the last tissue, all plates were transferred into the incubator for 35 minutes at 37 ± 1°C and 5.0 ± 1% CO2 and ≥ 95% rel-ative humidity. The plates were then left to stand at room temperature until the expiration of one hour (see deviation in chapter 11).
1 hour after the first application, the inserts were removed from the plates using sterile forceps and rinsed immediately in 1-minute-intervals.
After rinsing thoroughly with DPBS, each tissue was blotted with sterile cellulose tissue and then transferred into a new 6-well-plate with fresh assay medium (0.9 mL). The sur-face of the inserts was then carefully dried with a sterile cotton tipped swab.
Then, the tissues were set in the incubator for 25 hours at 37 ± 1°C and 5.0 ± 1% CO2 and ≥ 95% relative humidity.

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Average of Tissues 1-3

Value:

97.9

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 3

Value:

101.2

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 2

Value:

95.3

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 4

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 1

Value:

97.1

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

After the treatment with the test item, the mean value of relative tissue viability was reduced to 97.9%. This value is above the threshold for skin irritation potential (50%). Test items that induce values above the threshold of 50% are considered non-irritant to skin.

Therefore, the test item Stearinsäureanhydrid is considered non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.

Executive summary:

One valid experiment was performed.

Three tissues of the human skin model EpiDerm^TM were treated with the test item for 60 minutes (see deviation in chapter 11).

The test item was applied directly to each tissue and spread to match the tissue size (0.63 cm²; as indicated by the supplier).

DPBS-buffer was used as negative control and 5% SDS solution was used as positive control.

After treatment with the negative control, the mean absorbance value was within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8, OD was 1.537.

The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 5.4% (required: £ 20%).

The variation within the tissue replicates of negative control, positive control and test item was acceptable (required: ≤ 18%).