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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
Study period:
March 2018
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
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
4-amino-5-methyl-1,2-dihydropyridin-2-one
EC Number:
682-818-3
Cas Number:
95306-64-2
Molecular formula:
C6 H8 N2 O
IUPAC Name:
4-amino-5-methyl-1,2-dihydropyridin-2-one
Test material form:
solid

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Justification for test system used:
commercially available test method
Vehicle:
unchanged (no vehicle)
Details on test system:
RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: epiCS® (CellSystems, Troisdorf, Germany).
- Cat.-No: CS-1001

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: RT (room temperature)
- Temperature of post-treatment incubation (if applicable): Incubator temperature: 37 ± 2° C (CO2 gas concentration: 5 %; Humidity: maximum)

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1mg/ml
- Incubation time: 3 hours
- Spectrophotometer: EL808, Bio-Tek
- Wavelength: 570 nm

PREDICTION MODEL / DECISION CRITERIA:
- Corrosivity potential of test materials is predicted from the cell viabilities obtained after 3 min and 60 min treatment compared to the negative control. A chemical is classified "corrosive" (sub-category 1A) if the cell viability after 3 min treatment is decreased by more than 50 %. If cell viability after 3 min exposure is ≥ 50 %, while it is below 15 % after 60 min exposure the substance is also classified as corrosive, but sub-category 1 B/1 C. If cell viability after 3 min exposure is ≥ 50 % and after 60 min exposure ≥ 15 %, the substance is classified as non-corrosive.

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
Reliability of the test was previously confirmed by interlaboratory validation

Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 mg (plus 50 µl 0.9% NaCl to moisten and ensure good contact with the epidermis surface)

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 µl
- Concentration (if solution): 0.9% NaCl
Duration of treatment / exposure:
3 and 60 minutes
Number of replicates:
3

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
cell viability after 3 min [%]
Value:
ca. 110
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
cell viability after 60 min [%]
Value:
ca. 93
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Other effects / acceptance of results:
- OTHER EFFECTS:
- Visible damage on test system: No
- Direct-MTT reduction: No - according to the results of the pre-check
- Colour interference with MTT: No - according to the results of the pre-check

DEMONSTRATION OF TECHNICAL PROFICIENCY:
- Reliability of the test was previously confirmed by interlaboratory validation

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Any other information on results incl. tables

Table 1: Tabular summary of the results   

 Sample No.  Test item  Time (min)  OD mean *  Std Dev  % Viability
1 - 3  Negative control NaCl 0.9 %  60   2.05 0.07  100.00 
4 - 6 Positive control 8N KOH 60   0.01

0.00

0.38

13 - 15

4 -Amino-5-methylpyridon 

60

 1.90

0.04 

 93.02

16 - 18

Negative control NaCl 0.9 % 

3

 1.71

0.02

 100.00

25 - 27

4 -Amino-5-methylpyridon 

3

1.88

0.12

 109.87

* 6 values

Applicant's summary and conclusion

Interpretation of results:
other: negative
Executive summary:

A study for predicting a non-specific, corrosive potential of the test item by using reconstructed human epidermis (test method epiCS®) was performed according to OECD TG 431. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min. The MTT (Methylthiazoletetrazolium) viability test results (3 min.: 109.87 % viability; 60 min.: 93.02 % viability) showed, that the test item has no corrosive property under the conditions of the assay used.