Methanaminium, N-[4-[[4-(dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]-N-methyl-, ethanedioate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

other: read across from analogue substance

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The experiment is scientifically acceptable, nevertheless details about the tested substance composition are missing. Read across from a similar substance which has the same main component and with a different counter ion that does not influence the characteristics related to the specific end-point.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Malachite Green

IUPAC Name:

Malachite Green

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hagemann GmbH & C0
- Weight at study initiation: 2.4 kg
- Diet : Mummel Z ad libitum
- Water: ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: 16 - 18 °C
- Humidity: 40 %
- Photoperiod: 12 hrs cycle dark/light.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

500 mg of substance in water applied by a gaze of 2.5 x 2.5 cm

Duration of treatment / exposure:

4 h

Observation period:

8 days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 8 x 8 cm
- Type of wrap if used: double-layer surgical gauze, semiocclusive bendage.

REMOVAL OF TEST SUBSTANCE
- Washing: with water or olive oil.
- Time after start of exposure: 4 h

SCORING SYSTEM
Erythema and Eschar Formation
No erythema 0
Very slight erythema (barely perceptible) 1
Well defined erythema 2
Moderate to severe erythema 3
Severe erythema (beef redness) to eschar formation preventing grading of erythema 4
Maximum possible: 4

Oedema Formation
No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well defined by definite raising) 2
Moderate oedema (raised approximately 1 mm) 3
Severe oedema (raised more than 1 mm and extending beyond area of exposure) 4
Maximum possible: 4

Classification
0.0 - 0.5 not irritating
0.6 - 3.0 slightly irritating
3.1 - 5.0 moderately irritating
5.1 - 8.0 strongly irritating

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 3/3

Time point:

other: mean at 24, 48 and 72 hrs

Reversibility:

not fully reversible within: 8 days

Remarks on result:

other: substance-induced coloration of the skin

Results 2

Irritation parameter:

edema score

Basis:

animal: 3/3

Time point:

other: mean at 24, 48 and 72 hrs

Score:

< 2.3

Irritant / corrosive response data:

After the sample administrations the skin of the rabbit was coloured in green and oedema was not easily identifiable.
The substance was evaluated as strong irritating.

Other effects:

The substance leaves a dryness and atrophy; no recovery within 8 days.

Any other information on results incl. tables

Effect	Time after patch removal	Skin irritation/animal
Erythema	1 h	1	2	3
	24 h	*	*	*
	48 h	*	*	*
	72 h	*	*	*
	8 d	*	*	*
Oedema	1 h	0	0	0
	24 h	0	0	0
	48 h	0	0	0
	72 h	0	0	0
	8 d	0	0	0

* substance-induced coloration of the skin

Applicant's summary and conclusion

Conclusions:

Disregarded study

Executive summary:

White Newzeland Rabbits were chosen to test Malachite Green for skin irritation potential, following OECD Guideline 404. After application of 500 µl rabbits were observed for 1h, 24h, 48h, 72 hours up to 8 days. Erythema was not identified because the skin was colourful and the oedema was not found, but the rabbit skin was dry and atrophied, even after 8 days of observation. The substance was evaluated as strong irritating.

Conclusion

The experiment is scientifically acceptable, nevertheless details about the tested substance composition are missing.

The effects recorded were not fully evaluable and the recovering has been evaluated after only 8 days instead than 21 days. Furthermore, dryness is not clearly an irritating effect attributable to the test substance. Because of the lacking of relevant information from the assessment point of view, the study has been disregarded.