4-[[5-(anilino)carbonyl-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between the 7 December 2001 and 21 December 2001.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Test material

Test material information

Constituent 1

Reference substance name:

4-[[5-(anilino)carbonyl-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

EC Number:

260-152-0

EC Name:

4-[[5-(anilino)carbonyl-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

Cas Number:

56396-10-2

Molecular formula:

C25H20N4O4

IUPAC Name:

4-[[5-(anilino)carbonyl-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

Test material form:

solid: particulate/powder

Remarks:

(magenta)

Details on test material:

For all studies conducted on substance, where identifier was ST463, purity was stated as >98 - 99.9% (depending on batch)

Specific details on test material used for the study:

Identity:: ST463
Appearance: Magenta powder
Storage conditions: Room temperature
Lot number: 6558
Purity: 99.9%
Sample received: October 2002
Expiry: 15 0ctober 2001

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan U.K.Ltd. Bicester,Oxon, Engiand
- Age at study initiation: 8-11 weeks old
- Weight at study initiation: 214-262 g
- Housing: The rats were allocated without concious bias to cages within the treatment group. They were housed individually in metal cages (RS Biotech Sub-Divisible Rodent Cages - polished stainless steel). The cages were fitted with grid floors to ensure rapid removal of waste material to undertrays. The cages were suspended in mobile stainless steel racks.
- Diet (e.g. ad libitum): Standard laboratory rodent diet (Special Diet Services RM1(E) SQC expanded pellet) (ad libitum)
- Water (e.g. ad libitum): drinking water (ad libitum)
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12 hrs day/12 hrs night

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

corn oil

Details on dermal exposure:

Hair was removed from the dorso-lumbar region of each rat with electric clippers taking care to avoid damaging the skin,exposing an area equivalent to approxilnately 10% of the total body surface area.
The test substance was applied by spreading it evenly over the prepared skin. The treatnent area (approximately 50 mm x 50 mm) was covered with porous gauze held in place with a non-iritating dressing, and further covered by a waterproof dressing encircled firmly around the trunk of the animal. Treatment in this manner was performed on Day 1 (day of dosing) of the study only.

Duration of exposure:

24 hours - At the end of the 24 hours exposure period the dressing was carefully removed and the treated area of skin was washed mild detergent followed by warm water(30- 40°C) to remove any residual test substance. The treated area was blotted dry with absorbent paper.

Doses:

2000 mg/kg bodyweight

No. of animals per sex per dose:

5 animals per sex per dose (five males at 2000 mg/kg bodyweight and five females at 2000 mg/kg bodyweight)

Control animals:

no

Details on study design:

TEST SUBSTANCE PREPARATION:
The test item was formulated at a maximum practical concentration of 57% w/v in corn oil and administered at a dose volume of 3.51 ml/kg bodyweight.
The absorption of the test substance was not determined.
Characterisation of the homogeneity, stability and purity of the test substance was not undertaken in this studt and remained the responsibility of the Sponsor.

CONTROL ANIMALS:
No control animals were included in this study.

OBSERVATIONS:
Mortality:
Cages of rats were checked at least twice daily for mortalities.

Clinical signs:
Animals were observed soon after dosing and at frequent intervals for the remainder of Day 1. On subsequent days animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15 - morning only). The nature and severity of the clinical signs and time were recorded at each observations.
All animals were observed for 14 days after dosing.

Dermal responses:
Local dermal irritation at the treatment site was assessed daily using the following numerical 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 (beet redness) to eschar formation (injuries in depth) = 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 (raise more than 1 mm and extending beyond the area of exposure) = 4

Any lesion or reaction not covered by this scoring system was described.

Bodyweight:
The bodyweight of each rat was recorded on Days 1(prior to dosing), 8 and 15 bodyweight changes and group mean bodyweights were calculated.

TERMINAL STUDIES
Termination:
All animals were killed on Day 15 by carbon dioxide asphyxiation.

Macroscopic pathology:
All animals were subjected to a macroscoplc examination which consisted of opening the thoracic and abdominal cavities. The macroscopic appearance of all tissues was recorded.

Deviations from protocol:
There were no deviations from the protocol.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths following a single dermal application of the test item to a group of 10 rats (5 males and 5 females) at a dose level of 2000 mg/kg bodyweight.

Clinical signs:

other: Clinical signs were confined to dark cerise coloured faeces seen in all animals on Days 3 through 5. No other clinical signs of reaction to treatment were observed during the study.

Gross pathology:

Macroscopic examination revealed dark cerise staining at the dose site of 2 females. No other abnormalities were recorded at the macroscopic examination at study termination on Day 15.

Other findings:

Very slight dermal irritation (Grade l oedema) was observed in 1 male following removal of the dressings, resolving completely by Day 3. A residual cerise staining from the test material precluded assessment of erythema in all animals up to Day 11 or 13. In addition localised spots and/or scabbing was noted in 1 fernale on Day 9 and 10. No dermal irritation was observed in the remaining animals during the study.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute lethal dermal dose to rats of the test item was demonstrated to be greater than 2000 mg/kg bodyweight.

Executive summary:

A study was performed to assess the acute dermal toxicity of the test item to the rat. The method followed was that described in:

• EEC Methods for the determination of toxicity, Annex to Directive 92/69/EEC (Official Journal No. L383A, 29.12.92), Part B, Method B.3. Acute toxicity (dermal).
• OECD Guideline for Testing of Chemicals No. 402 "Acute Dermal Toxicity". Adopted: 24 February 1987.

A group of 10 rats (5 males and 5 females) received a single topical application of the test substance, formulated at a maximum practical concentration in corn oil, at a dose level of 2000 mg/kg bodyweight, for a duration of 24 hours. All animals were killed and examined macroscopically on Day 15, the end of the observation period.

Clinical signs were confined to dark cerise coloured faeces seen in all animals on Days 3 through 5. No other clinical signs of reaction to treatment were observed during the study.

Very slight dermal irritation (Grade 1 oedema) was observed in 1 male following removal of the dressings, resolving completely by Day 3. A redisual cerise staining from the test material precluded assessment of the erythema in all animals up to Day 11 or 13. In addition localised spots and/or scabbing was noted in 1 female on Day 9 and 10. No dermal irritation was observed in the remaining animals during the study.

Low bodyweight gains were noted in 1 male and 4 females on Day 8 (Nos. G2, G6, G7, G8 and G9) and for 3 females on Day 15 (Nos. G6, G7 and G9). All other animals were considered to have achieved satisfactory bodyweight gains throughout the study.

Macroscopic examination revealed dark cerise staining at the dose site of 2 females. No other abnormalities were recorded at the macroscopic examination at study termination on Day 15.

The acute lethal dermal dose to rats of the test item was demonstrated to be greater than 2000 mg/kg bodyweight.