Urea, reaction products with formaldehyde and glyoxal

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD: Draft Proposal for a New Guideline on In Vitro Skin Irritation: human Skin Model Test of 06-Jun-2008

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): Fixapret CP konz., PBG = 10073662, after Concentration
- Analytical purity: 93.4 %
- Lot/batch No.: 000335MACA0

Test animals

Species:

other: EpiDerm TM Skin Corrosivity Test

Strain:

other: not applicable

Test system

Type of coverage:

other: not applicable

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 20 mg of the test substance

Duration of treatment / exposure:

1 hour

Observation period:

not applicable

Number of animals:

not applicable

Details on study design:

TEST SYSTEM
The EpiDermTM model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multi layered, 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 EpiDermTM tissues (surface 0.6 cm²) are cultured on specially prepared cell culture inserts (MILLICELLs®, 10 mm ∅) and commercially available as kits (EpiDerm™ 200), containing 24 tissues on shipping agarose.

TEST PROCEDURE
Three EpiDerm™ tissue samples were incubated with the test substance for 1 hour followed by a 42-hours post-incubation period.
Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/ post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as suitable endpoint. The formazan production of the testsubstance treated epidermal tissues is compared to that of negative control tissues. The quotient of both values indicates the relative tissue viability.

CONTROLS
-Negative control (NC): PBS, sterile
-Positive control (PC): 5 % sodium dodecyl sulfate (SDS, Sigma,Germany in highly de-ionized water, sterile

ASSAY ACCEPTANCE CRITERIA:
-Negative control (NC): mean OD570 of the NC is ≥ 1.0.
-Positive Control (PC): 5% SDS is used as PC and reflects the sensitivity of the tissues used in the test conditions. A viability of ≤ 20% is acceptable.

-Tissue variability: For every treatment, 3 tissues are treated in parallel. The inter-tissue variability is considered to be acceptable if the SD of %-viability is ≤ 20.

Results and discussion

Any other information on results incl. tables

Test article		Tissue 1	Tissue 2	Tissue 3	Mean	SD
NC	Mean OD570	1.8343	1.5913	1.8213	1.7490
	Viabillity [% of NC]	104.9	91.0	104.1	100	7.82
09/0299-1	Mean OD570	1.8938	1.6333	1.8823	1.8032
	Viabillity [% of NC]	108.3	93.4	107.6	103	8.42
PC	Mean OD570	0.1428	0.1698	0.1383	0.1503
	Viabillity [% of NC]	8.2	9.7	7.9	9	0.97

 

The EpiDerm skin irritation test showed the following results:

The test substance is not able to reduce MTT directly.

The mean viability of the test-substance treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 103%.