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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 March 2010 to 2 April 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD 431 In vitro skin corrosion: human skin model test (adopted 13 April 2004 :
Deviations:
not specified
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): dineodymium tricarbonate
- Substance type: powder
- Physical state: extremely pale purple powder
- Lot/batch No.: not provided
- Expiration date of the lot/batch: 15 Feb 2011
- Storage condition of test material: room termperature in the dark over silica gel

Test animals

Species:
human
Strain:
other: human-derived keritoncytes
Details on test animals and environmental conditions:
IN VITRO MODEL
- Source: Episkin Model Kit from SkinEthic Laboratories, Nice france
- Date received: 30 Mar 2010
- Description: The EPISKINTM model is a three-dimensional reconstituted human epidermis model consisting of adult human-derived epidermal keratinocytes seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen. A highly differentiated and stratified epidermis model is obtained after a 13 day culture period comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum.

Test system

Type of coverage:
other: applied topically
Preparation of test site:
other: in vitro cells
Vehicle:
unchanged (no vehicle)
Controls:
other: Negative control (NaCL) and positve control (glacial acetic acid)
Amount / concentration applied:
TEST MATERIAL
- Concentration: 20 mg of test material added to 2.2 mL of a 0.3 mg/mL MTT (yellow tetrazolium salt) solution solution freshly prepared and incubated in the dark at room temperature

VEHICLE
- Concentration: 0.3 mg/mL MTT
Duration of treatment / exposure:
3, 60 an 240 minutes (test material)
240 min (negative and postive control)
Observation period:
After removal of test material and tissue was rinsed the MTT solution was added and tissues were incubated for 3 h at room temperature (protected from light)
Details on study design:
Duplicate tissues were treated with the test material for exposure periods of 3, 60 and 240 minutes. At the end of the exposure period the test material was rinsed from each tissue before each tissue was taken for MTT-loading. After MTT loading a total biopsy of each epidermis was made and placed into micro tubes containing acidified isopropanol for extraction of formazan crystals out of the MTT-loaded tissues.

At the end of the formazan extraction period each tube was mixed thoroughly and duplicate 200 µl samples were transferred to the appropriate wells of a pre-labelled 96 well plate. The optical density was measured at 540 nm.

Data are presented in the form of percentage viability (MTT reduction in the test material treated tissues relative to negative control tissues).

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
other: other: corrosion
Value:
100.4
Remarks on result:
other:
Remarks:
Basis: mean relative viability of tissues (percent). Time point: 240. Remarks: Non-corrosive. (migrated information)
Irritation / corrosion parameter:
other: other: corrosion
Value:
107.4
Remarks on result:
other:
Remarks:
Basis: mean relative viability of tissues (percent). Time point: 60. Remarks: Non-corrosive. (migrated information)
Irritation / corrosion parameter:
other: other: corrosion
Value:
91.4
Remarks on result:
other:
Remarks:
Basis: mean relatvie viability of tissues. Time point: 3. Remarks: Non-corrosive. (migrated information)

Any other information on results incl. tables

Table1            Mean OD540Values and Viabilities for the Negative Control, Positive Control Material and Test Material

Material

Exposure Period

Mean OD540of duplicate tissues

Relative mean viability (%)

Negative Control Material

240 Minutes

0.243

100*

Positive Control Material

240 Minutes

0.010

4.1

Test Material

240 Minutes

0.244

100.4

60 Minutes

0.261

107.4

3 Minutes

0.222

91.4


*=     The mean viability of the negative control tissues is set at 100%

Table2            Qualitative Evaluation of Tissue Viability (MTT uptake visual evaluation)

Material

Exposure Period

Tissue 1

Tissue 2

Negative Control Material

240 Minutes

-

-

Positive Control Material

240 Minutes

++

++

Test Material

240 Minutes

-

-

60 Minutes

-

-

3 Minutes

-

-

MTT Visual Scoring Scheme of SkinEthic Tissues

-     =  Blue tissue (viable)

+    =  Blue/white tissue (semi-viable)

++  =  Tissue completely white (dead)

Applicant's summary and conclusion

Interpretation of results:
other: non-corrosive
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
The test material was considered to be Non-Corrosive to the skin and accredited the EU risk phrase of No label and a UN packing group Non-Corrosive.
Executive summary:

In the in vitro skin corrosivity potential test with the EpiskinTM reconstituted human epidermis model (according to OECD 431) dineodymium tricarbonate was tested for 3, 60, and 240 minutes. The EpiskinTM model is able to distinguish between corrosive and non-corrosive chemicals for purposed of UN and EU labeling. Duplicate tissues were treated. At the end of exposure viability was assessed based on the MTT reduction in the test material treated tissues relative to the negative control tissues. The relative mean viabilitiy of the test material treated materials was 100.4%, 107.4%, and 91.4% after 240, 60, and 3 minutes. The test material was considered to be NON-Corrosive to the skin and accredited the EU risk phrase of NO label and a UN packing group Non-Corrosive.