Fenspiride

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

7 to 21st April 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Skin corrosion refers to the production of irreversible tissue damage in the skin following the application of a test material [as defined by the Globally Harmonised System for the Classification and Labelling of Chemical Substances and Mixtures (GHS)].
Validation studies have shown that tests employing human skin models are able to discriminate between known skin corrosives (Optional sub-category 1A, optional sub-category 1B and 1C) and non-corrosives. The test protocol may also enable the distinction between severe and less severe skin corrosives.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

GLP compliance:

yes (incl. QA statement)

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

Skin corrosion refers to the production of irreversible tissue damage in the skin following the application of a test material [as defined by the Globally Harmonised System for the Classification and Labelling of Chemical Substances and Mixtures (GHS)].
Validation studies have shown that tests employing human skin models are able to discriminate between known skin corrosives (Optional sub-category 1A, optional sub-category 1B and 1C) and non-corrosives. The test protocol may also enable the distinction between severe and less severe skin corrosives.

Vehicle:

water

Control samples:

yes, concurrent negative control

Amount/concentration applied:

25 μL of deionised water and 25 ± 2mg (39.7 mg/cm2) of the test item were applied onto the surface of duplicate EpiDermTM tissue.

Duration of treatment / exposure:

Duplicate EpiDermTM tissues were treated with the test item, positive control or negative control for the following exposure times:
• Test Item: 3 ± 0.5 minutes, 60 ± 5 minutes
• Negative Control: 3 ± 0.5 minutes, 60 ± 5 minutes
• Positive Control: 3 ± 0.5 minutes, 60 ± 5 minutes
After the pre-incubation of the EpiDermTM tissues was completed the DMEM-based medium in each well was replaced with 0.9 mL fresh assay medium. The 6-well plates for the 3 ± 0.5 minutes exposure periods stayed at room temperature in the sterile bench, the 6-well plates for the 60 ± 5 minutes exposure period were placed into an incubator (37 ± 1.5 °C, 5 ± 0.5% CO2).
At the end of the exposure period the tissues were removed from the 6-well plate and gently rinsed using a wash bottle / multipipette containing DPBS to remove any residual test material (20 times). Excess DPBS was removed by gently shaking the tissue insert and blotting the lower surface with blotting paper. The tissues were placed in the prepared holding plate until all tissues were rinsed.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

other: Relative absorbance (%)

Run / experiment:

3 min

Value:

ca. 86.5

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

other: Relative absorbance (%)

Run / experiment:

1 hour

Value:

ca. 97.7

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

This in vitro study was performed to assess the corrosive potential of 428 BASE BRUTE by means of the Human Skin Model Test with EpiDerm™ tissues models.

The test item passed the MTT- and the colour interference pre-tests.

Independent duplicate tissues of EpiDermTM were exposed to the test item, the negative control (deionised water) or the positive control (8.0 N KOH) for 3 minutes and 1 hour, respectively.

Afterwards, the test and the control items were rinsed off the tissues, and a 3 hour incubation period (37 ± 1 °C, 5 ± 0.5 % CO2) with MTT solution followed. MTT solution was then aspirated from the wells and the wells were rinsed with DPBS. Inserts were transferred into new 24 well plates. The formazan salt was extracted for about 19.5 hours at room temperature.

The required acceptability criteria were met.

Exposure to the positive control induced a decrease in the relative absorbance as compared to the negative control, both for the 3 minutes exposure period (24.0%) and for the 1 hour exposure period (9.6%) thus confirming the validity of the test system and the specific batch of tissue models.

After exposure to the test item 428 BASE BRUTE the relative absorbance value decreased to 86.5% after 3 minutes exposure. After 1 hour exposure the relative absorbance value was reduced to 97.7%. Both values did not affect the threshold for corrosivity which is defined to be 50% after the 3 minutes exposure and 15% after the 1 hour exposure. Therefore, the test item is not considered to be corrosive.

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 reported experimental conditions, the test item 428 BASE BRUTE is non corrosive to skin according to EU CLP and UN GHS.

Executive summary:

After exposure of the tissues to the test item the relative absorbance value decreased to 86.5% after 3 minutes exposure. After 1 hour exposure the relative absorbance value was reduced to 97.7%. Both values did not affect the threshold for corrosivity which is defined to be 50% after the 3 minutes exposure and 15% after the 1 hour exposure. Therefore, the test item is not considered to be corrosive.

In conclusion, it can be stated that in this study and under the reported experimental conditions, the test item 428 BASE BRUTE is non corrosive to skin according to EU CLP and UN GHS.