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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Remarks:
in vitro
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011-06-17 - 2011-08-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study (GLP)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)
Version / remarks:
adopted July 19, 2006
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Methyl-Diamino-Cyclohexan; Lab test item number: 10/0117-1
- Physical state: liquid, colourless to yellowish, clear
- Analytical purity: 98.5 mol% (NMR-spectroscopy)
- Lot/batch No.: 84407247G0
- Stability under test conditions: the stability under storage conditions over the study period was guaranteed.
- Storage condition of test material: room temperature (N2 conditions)
- Other: the test substance was homogeneous by visual inspection
- pH-value: ca. 8 (undiluted test substance)

Test animals

Species:
other: in vitro test on a reconstituted collagen matrix (Corrositex® Biobarrier Membrane).
Strain:
other: not applicable (in vitro test)
Details on test animals and environmental conditions:
Not applicable

Test system

Type of coverage:
open
Preparation of test site:
other: not applicable
Vehicle:
unchanged (no vehicle)
Controls:
other: not applicable
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): approximately 500 μL of the test substance was added onto the membrane disc
Duration of treatment / exposure:
Not applicable
Observation period:
until breakthrough of the test substance through the membrane disc coated with the biobarrier matrix.
Number of animals:
not applicable
Details on study design:
I TEST SYSTEM
- The Corrositex® assay kit is commercially available from InVitro International.
- The assay is based on the time that is required for the test substance to penetrate through the Corrositex® Biobarrier Membrane and produce a change in the Chemical Detection System (CDS).
- The Corrositex® assay is used to determine the corrosive potential of test substances. The assay is limited to testing those materials which cause detectable pH changes in the CDS
II Pretext
- Qualification screen (to determine if a color change can be detected): 150 μL of the test substance was added to the CDS screening tube. If the test substance failed to produce a color change in the CDS within one minute, the test substance could not be analyzed in this system, and no further testing was required.
- Categorization screen (to categorize weak acids/bases and strong acids/bases): the categorization screen was performed by adding 150 μL of test substance to each tube A and B. Each tube was mixed and the resulting color observed. If required, 2 drops of the "confirm" reagent were added to tube B, the tube mixed, and the resulting color observed. The test substance was scored as category 1 (high acid/alkaline reserve) or category 2 (low acid/alkaline reserve).

III MAIN TEST (Corrositex®)
- Biobarrier preparation: the vial containing the biobarrier matrix powder was placed in a water bath at 64 – 68ºC. The entire content of the biobarrier diluent vial was added slowly to the matrix powder (stir bar rotation) to avoid foaming of the solution. 200 μL of the solubilized matrix was pipetted into each of the membrane discs, and the membrane discs were then refrigerated for at least 2 hours at 2 – 8ºC. The biobarriers were wrapped and stored at 2 – 8ºC for a maximum of 7 days.
- Corrositex® assay (after acceptance of the positive control)
Four vials containing the CDS were used for the test substance. In addition, one vial was used for the PC, NC and for the color (blank) control, each.
a) A membrane disc coated with the biobarrier matrix was placed into one vial containing the CDS and approximately 500 μL of the test substance was added onto the membrane disc. An electronic time clock was started with the application. The vial was observed for three minutes for any change in the CDS.
b) If no color change was observed within three minutes, the remaining membranes were treated with the test substance. An electronic time clock was started with each application. The vials were observed continuously for the first ten minutes. Thereafter the vials were observed for approximately ten minutes around the time points relevant for evaluation or until breakthrough of the test substance occurred. The elapsed time between test-substance application and the first change in the indicator solution (i.e. barrier penetration) was recorded.
c) The positive control vial was prepared as described above and received one pellet of sodium hydroxide on top of the membrane disc. This vial was monitored continuously until breakthrough had occurred.
The negative control vial was prepared as described above and received 500 μL of 10% citric acid. This vial was observed for 60 minutes and was evaluated as “non-corrosive” if no reaction had been observed.

IV SCORING SYSTEM
- Corrosive potential was determined on the basis of the average time recorded for the test substance to produce a change in the CDS (see Table 1).
- Acceptance criteria: The Corrositex® assay was accepted if the breakthrough time for the positive control substance was in the historic control range (mean ± 2-3 x standard deviations). To demonstrate the functional integrity of the membrane barrier, the acceptance criterion for the negative control was not to induce membrane breakthrough within a 60 min observation period.

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
penetration time (in minutes)
Value:
6.3

Any other information on results incl. tables

Table 2: Summary of the findings

 

Breakthrough time (min:s)

 

Vial 1

Vial 2

Vial 3

Vial 4

Mean

Test substance

5:01

4:35

7:30

8:10

6:19

Positive control

10:14

-

-

-

-

Negative control

NB

-

-

-

-

NB = no break through within maximum observation period (60 min)

Applicant's summary and conclusion