3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethylxanthylium chloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 September 2016 to 30 September 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2015

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

2008 including most recent amendments

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Version / remarks:

1998

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: JMAFF, 12 Nousan, Notification No 8147

Version / remarks:

2000 including the most recent partial revisions

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethylxanthylium chloride

EC Number:

221-326-1

EC Name:

3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethylxanthylium chloride

Cas Number:

3068-39-1

Molecular formula:

C27H29N2O3.Cl

IUPAC Name:

3,6-bis(ethylamino)-9-[2-(methoxycarbonyl)phenyl]-2,7-dimethylxanthylium chloride

Test material form:

solid: particulate/powder

Details on test material:

- Appearance: Brown red powder
- Storage conditions of test material: At room temperature
- Stable until: 10 June 2021 (expiry date)

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: At start of dosing, the animals were between 12 and 24 weeks old
- Weight at study initiation: At start of dosing, body weights were at least 1.5 kg
- Housing: Animals were individually housed in cages with perforated floors (dimensions 67 x 62 x 55 cm) and shelters (dimensions 40 x 32 x 23 cm).
- Diet: Pelleted diet for rabbits approximately 100 grams per day. Hay and wooden sticks were available during the study period.
- Water: ad libitum access to tap water
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18 to 24 °C
- Humidity: 40 to 70 % (relative)
- Air changes: at least 10 air changes per hour
- Photoperiod: 12-hour light/12-hour dark cycle

IN-LIFE DATES: Not reported

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

other: watery ethanol (50 % v/v)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 mL. Since the test material did not mix with water, the powdery test material was moistened with watery ethanol (50 % v/v) immediately before application, to ensure close contact with the animal's skin.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3; the study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). The two other animals were treated in a similar manner 1 week later, after considering the degree of skin irritation observed in the first animal.

Details on study design:

TEST SITE
- Area of exposure: Flank. Approximately 24 hours before treatment, the dorsal fur was clipped with electric clippers, exposing an area of approximately 150 square centimetres (10 x 15 cm).
- Type of wrap if used: The test material was applied to the skin of one flank, using a patch of 2 x 3 cm. The patch was mounted on tape which was wrapped around the abdomen and secured with elastic bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the skin cleaned of residual test material using tap water and watery ethanol (50 % v/v) and watery acetone (50 % v/v).
- Time after start of exposure: Four hours after the application

OBSERVATION TIME POINTS
The skin reactions were assessed at approximately 1, 24, 48 and 72 hours after the removal of the dressings and test item. The irritation scores and a description of all other (local) effects were recorded.

SCORING SYSTEM:
To facilitate scoring, treated skin areas were re-clipped and cleaned of residual test material using watery acetone (50% v/v) at least 3 hours before the observations.
- Method of calculation: The irritation was assessed according to the following numerical scoring system. At each observation, the highest scores given were recorded.

Erythema and Eschar Formation
0 = No erythema
1 = Very slight erythema (barely perceptible)
2 = Well-defined erythema
3 = Moderate to severe erythema
4 = Severe erythema (beef redness; where signs of necrosis or corrosion (injuries in depth) prevent erythema scoring, the maximum grade for erythema is given)

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

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: Not applicable

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: Not applicable

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No skin irritation was observed after 4 hours of exposure to the test material. There was no evidence of a corrosive effect on the skin.

Other effects:

Pink staining of the treated skin by the test material was observed throughout the study period, which hampered the scoring for erythema on Day 1 only (1 hour observation). There was no effect on the conclusion of the study, since sufficient observations were available for interpretation.
No signs of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified in accordance with EU criteria

Conclusions:

Under the conditions of this study, the test material is not considered to cause corrosion or irritation to the skin.

Executive summary:

A primary skin irritation/corrosion study was conducted in the rabbit in accordance with the standardised guidelines OECD 404, EU Method B.4, US EPA OPPTS 870.2500 and JMAFF 12 Nousan Notification No 8147 under GLP conditions.

Three rabbits were exposed to 0.5 grams of the test material moistened with 0.5 mL 50 % watery ethanol. The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). The two other animals were treated in a similar manner 1 week later, after considering the degree of skin irritation observed in the first animal. The test material was applied onto clipped skin for 4 hours using a semi-occlusive dressing. Skin reactions were assessed 1, 24, 48 and 72 hours after exposure.

No skin irritation was observed after 4 hours of exposure to the test material. Pink staining of the treated skin by the test material was observed throughout the study period, which hampered the scoring for erythema on Day 1 only (1 hour observation point). There was no effect on the conclusion of the study, since sufficient observations were available for interpretation.

Under the conditions of this study, the test material is not considered to cause corrosion or irritation to the skin.