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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline

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:
EpiSkin from SkinEthic Laboratories France.
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
20 mg
Duration of treatment / exposure:
3, 60 and 240 minutes
Duration of post-treatment incubation (if applicable):
3 hour incubation with MTT
Number of replicates:
Two

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3 min exposure
Value:
90.83
Vehicle controls valid:
not applicable
Negative controls valid:
yes
Positive controls valid:
yes
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
60 min exposure
Value:
96.64
Vehicle controls valid:
not applicable
Negative controls valid:
yes
Positive controls valid:
yes
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
240 min exposure
Value:
92.23
Vehicle controls valid:
not applicable
Negative controls valid:
yes
Positive controls valid:
yes
Other effects / acceptance of results:
he absolute mean OD570 of the negative control tissues was 0.9712, 0.8067 and 0.9037 for the 3 -minute, 60 -minute and 240 -minute exposures, respectively.

Any other information on results incl. tables

Mean OD values of individual epidermis units.

3 -minutes exposure

      Adsorption (OD570)
   R1  R2
Negative control   1,0449

 0,9851

 Test item

 0,9804

0,8715 

 

60 -minutes exposure

        Adsorption (OD570)
   R1  R2
 Negative control  0,8406 0,8605 
 Test item  0,8172 0,8297 

240 -minute exposure

          Adsorption (OD570)
Negative control   0,9423 0,8527 
Positive control  0,0840 0,0788 
Test item  0,8786 0,8759 

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
After 240 -minute exposure in the Reconstructed Human Epidermis model the test item showed tissue viability 92.23%. Taken together, methylthiouracil is non-corrosive in the in vitro skin corrosion test performed according to OECD 431 guideline.
Executive summary:

The test item, methylthiouracil, was tested for its possible skin corrosion potential using a three dimensional Reconstructed Human Epidermis model, EpiSkin, through topical application. The study was perfomed according to OECD 431 guideline. The absolute mean OD570 of the negative control tissues was 0.9712, 0.8067 and 0.9037 for the 3 -minute, 60 -minute and 240 -minute exposures, respectively. The positive control has a mean cell viability of 4.16 % after 240 -minute exposure. Thus, the results of the controls indicate that the test system functioned properly.

After 240 -minute exposure the test item showed tissue viability 92.23%. Taken together, the test item methylthiouracil is non-corrosive in the in vitro skin corrosion test.