Registration Dossier

Toxicological information

Skin irritation / corrosion

Currently viewing:

Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
January 24th - February 22nd, 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))
Version / remarks:
Official Journal of the European Union No. L142, 31 May 2008.
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
Version / remarks:
adopted 13 April 2004
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
- Appearance: clear, slightly yellowish to brown, viscous liquid
- Storage condition of test material: at room temperature in the dark

Test animals

Species:
human
Details on test animals and environmental conditions:
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 36.3 – 37.0
- Humidity (%): 72 – 88

Test system

Vehicle:
unchanged (no vehicle)
Amount / concentration applied:
TEST MATERIAL
- Volume applied: 50 μl

NEGATIVE CONTOL:
- Volume applied: 25 µl milliQ.

POSITIVE CONTROL
- Volume applied: 50 µl
- Concentration: 8N KOH
Details on study design:
TEST SITE
- EpiDerm Skin Model (EPI-200, Lot no.:16850 kits A and B). The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm²) were cultured on polycarbonate membranes of 10 mm cell culture inserts. The model was obtained from MatTek Corporation, Ashland MA, U.S.A.

REMOVAL OF TEST SUBSTANCE
- Washing: phosphate buffered saline
- Time after start of exposure: 3 minutes or 1 hour

POST INCUBATION PERIOD
- 3 hours

SCORING SYSTEM:
- Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment. Cell viability was calculated for each tissue as a percentage of the mean of the negative control tissues.

BACKGROUND:
- Accelerator (PT 25E or PT 25E/2) was checked for possible direct MTT reduction in the Skin irritation test using EpiskinTM as a skin model (project 501366). Because a colour change was observed it was concluded that Accelerator (PT 25E or PT 25E/2) did interact with MTT. In addition to the normal 1-hour procedure, one freeze-killed tissue treated with test substance and one freeze-killed non treated tissue must be used for the cytotoxicity evaluation with MTT.

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3-minute exposure
Value:
85
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Remarks:
100%
Positive controls validity:
valid
Remarks:
14%
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
1-hour exposure
Value:
56
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Remarks:
100%
Positive controls validity:
valid
Remarks:
8%

Any other information on results incl. tables

Accelerator (PT 25E or PT 25E/2) was checked for possible direct MTT reduction in the Skin irritation test using EpiskinTM as a skin model (project 501366). Because a colour change was observed it was concluded that Accelerator (PT 25E or PT 25E/2) did interact with MTT. In addition to the normal 1-hour procedure, one freeze-killed tissue treated with test substance and one freeze-killed non-treated tissue was used for the cytotoxicity evaluation with MTT. In the present experiment no non-specific reduction was measured.

Applicant's summary and conclusion

Interpretation of results:
other: Not corrosive in the in vitro skin corrosion test
Conclusions:
An in vitro skin corrosion test was conducted according to OECD guideline 431 and GLP principles. It is concluded that this test is valid and that the test substance is not corrosive in the in vitro skin corrosion test.
Executive summary:

In an in vitro skin corrosion test using a human skin model (EpiDerm Skin Model) according to OECD guideline 431 and GLP principles, the influence of Accelerator (PT 25E or PT 25E/2) on the viability of human skin was tested. The test substance was applied directly to 0.6 cm2 cultured skin (25mg, in presence of 25 μl Milli-Q water). After 3 minutes or 1 hour, the substance was removed and cells were cultured for 3 hours in the presence of MTT. The viability of the cells was tested by reduction of MTT. Survival of unexposed skin was set at 100%, the positive control had a mean cell viability of 14% and 8% after resp. 3 minutes or 1 hour exposure whereas the test substance showed cell viability of 85% and 56% resp. Since the mean relative tissue viability after exposure to the test substance was above 50% or 15% after resp. 3 minutes or 1 hour exposure, it can be concluded that the test substance is not corrosive in the in vitro skin corrosion test.