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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:
13.08. - 14.08.2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Method B. 40. Skin corrosion (in vitro)
Version / remarks:
Published in O.J. L 142, 2008
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material (as cited in study report): Semi Dry Absorption (SDA) Product
- Molecular formula (if other than submission substance): not available
- Molecular weight (if other than submission substance): not available

Composition of test substance:
Calcium sulphate 6.49 %
Calcium sulphite 41.40 %
Calcium carbonate 29.50 %
Calcium hydroxide 2.27 %
Calcium chloride 17.98 %
Calcium fluoride 0.57 %
Oxides (SiO2 + Al2O3 + Fe2O3 + TiO2) sum 0.97 %
Sum of toxic metals: As, Be, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se, Tl, V, Zn sum < 0.1 %

Batch No.: SDA/0609/Sk
Appearance: White solid powder
Stability / Expiration date: 15 years (06/2024)
- Stability under test conditions: stable
- Storage condition of test material: the substance was stored in PE container at room temperature.
- Other: pH 11 approx. (by contact of application form with universal indicator pH strip moistened with water, strip producer Lach-Ner, s.r.o. Neratovice)

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
other: normal human-derived epidermal keratinocytes
Vehicle:
water
Details on test system:
RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: human skin model a reconstructed human epidermal model EpiDerm™ (EPI-200, MatTek, Ashland, USA)
- Tissue batch number(s): No. 12233, kit E

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37±1°C
- Temperature of post-treatment incubation (if applicable): 37±1°C

REMOVAL OF TEST MATERIAL AND CONTROLS
tissues were thoroughly rinsed and blotted to remove the test substance

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration:
tissues were transferred to 24-well plates containing MTT medium (1 mg·mL-1)
- Incubation time: 3 hrs
- Spectrophotometer: Libra S22. Isopropyl alcohol serves as a blank.
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION:
1. Direct MTT reduction: the test substance did not reduce MTT directly.
2. MTT test

DECISION CRITERIA
According to the OECD TG 431 as well as to the EU Method B.40, the test substance is considered to be corrosive to skin:
i) if the viability after 3 minutes exposure is less than 50 %, or
ii) if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15 %.
The test substance is considered to be non-corrosive to skin:
i) if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is greater than or equal to 15 %
Control samples:
yes, concurrent vehicle
yes, concurrent positive control
Amount/concentration applied:
TEST MATERIAL
Test substance (25 mg) was placed directly atop the tissue previously moistened with 25 μl of sterile water for injection to improve contact of the tissue surface with the test chemical. The material was not grinded and it was spread on the tissue surface.

VEHICLE
Water for injection - Ardeapharma a.s.
Lot No. 0101030309

NEGATIVE CONTROL
Water for injection - Ardeapharma a.s.

POSITIVE CONTROL
KOH 8N, solution prepared in laboratory
Duration of treatment / exposure:
3 min. and 60 min.
Duration of post-treatment incubation (if applicable):
24 + 18 hrs
Number of replicates:
3

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
% tissue viability
Value:
96.4
Negative controls validity:
valid
Positive controls validity:
valid
Other effects / acceptance of results:
All assay acceptance criteria have been met.
Negative control: The assay meets the acceptance criterion - the mean OD570 of the NC tissues was 1.482 (3 min) and 1.441 (60 min) what is ≥ 1.0 and ≤ 2.5.
Positive control: Viability of tissues treated with 8N KOH after 60 minutes treatment was 9.1 % what is ≤ 20%.

Applicant's summary and conclusion

Conclusions:
In the experiment arrangement given above, the test substance Semi Dry Absorption (SDA) Product was not corrosive in EpiDermTMmodel.
Executive summary:

Test substance Semi Dry Absorption (SDA) Product was assayed for the in vitro skin corrosion in human epidermal model EpiDermTM. The test was performed according to Method B. 40. Skin corrosion (in vitro), Council Regulation (EC) No.440/2008. Published in O.J. L 142, 2008.

The test substance (25 mg) was placed atop the tissue previously moistened with 25 μl of sterile water. Length of exposition was 3 and 60 minutes. Nine tissues were used for the experiment in each time, three per test substance (TS), three for positive control (PC) and three for negative control (NC).

After rinsing, tissues were incubated with MTT for three hours and extracted overnight subsequently at room temperature without shaking. OD570 of isopropanol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues. 

In the experiment arrangement given above, the test substance Semi Dry Absorption (SDA) Product was not corrosive in EpiDermTMmodel.