Reaction products of cyclohexylamine and 4-alkylaniline and 1,1'-methanediylbis(4-isocyanatobenzene)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 1996-01-17 to 1996-02-08

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP study in accordance with recognised test guideline but: Lot/batch No.: not stated Expiration date of the lot/batch: not stated NOTE: study deemed acceptable because spectral data for A-3622 are available, covering before and after the test period - see section 1.4 Analytical Information.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

92/96/EEC

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Specific details on test material used for the study:

- Physical state: fine, cream, cohesive powder
- Storage condition: ambient temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Limited, Margate, Kent, England

- Age at study initiation: The male animals were approximately seven to eight weeks old and the females were approximately ten to eleven weeks old.

- Weight at study initiation: in the range 196 - 209 g for males and 204 - 219 g for females.

- Fasting period before study: not applicable

- Housing: stainless steel grid cages (RS Biotech, Northants, England). The grid floors ensured rapid removal of waste material to undertrays which were cleaned as necessary. Five animals of the same sex were housed in each cage. The cages were suspended in mobile stainless steel racks.

- Diet (e.g. ad libitum): commercially-available complete pelleted rodent diet (RM I(E) SQC, from Special Diets Services Limited, Witham, Essex, England) was fed without restriction. The diet contained no added antibiotic or other chemotherapeutic or prophylactic treatment.

- Water (e.g. ad libitum): free access to tap water taken from the public supply

- Acclimation period: at least five days was allowed before administration of the test material.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21°C (range 19- 25°C)

- Humidity (%): 55% RH (range 40%-70% R.H),

- Air changes (per hr): at least 10 complete air changes per hour without recirculation

- Photoperiod (hrs dark / hrs light): lighting cycle of 12 hours of artificial light per day.


IN-LIFE DATES: From: 25 January 2009 To: 8 February 2009

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 5 cm x 5 cm

- % coverage: approximately 10% of the body surface area

- Type of wrap if used: The test material was applied to the skin by a 5 cm x 5 cm gauze patch. and occluded with aluminium foil. The foil was kept in place and protected by a pad of cotton wool and a bandage of waterproof plaster and tape wrapped twice around the trunk of the body with sufficient tension to ensure the dose remained securely in place.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): the dermal site was gently wiped with wet disposable tissues to remove residual test material.

- Time after start of exposure: the dressings were removed 24 hours after administration


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): the quantity of dose was determined for each animal according to its bodyweight on the morning of dosing, however volumes or weights are not stated in the report.

Duration of exposure:

24 hours

Doses:

maximum practicable dosage of 2000 mg/kg (Regulatory Limit test).

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: three separate recordings of signs were made during the first hour after administration and two further recordings during the remainder of Day 1. From Day 2 onwards, the animals were inspected twice daily and recordings of systemic and local signs were made once daily. The type, time of onset and duration of reactions to treatment were recorded.

- Necropsy of survivors performed: yes. All body cavities were opened, larger organs were sectioned and the gastrointestinal tract was opened at intervals for examination of the mucosal surfaces. All abnormalities were described or the normal appearance of major organs was confirmed. Each dermal application site was examined in situ, and in macroscopic section to obtain more information on dermal effects of treatment.

- Other examinations performed: The bodyweight of each animal was recorded on the day before dosing and on Days 1, 8 and 15. Macroscopically abnormal tissues were preserved in 4% neutral buffered fonnaldehyde and retained against future possible histopathological requirements.

Statistics:

not applicable

Results and discussion

Preliminary study:

A preliminary study was carried out using one female rat given A-3622 at a dosage of 2000 mg/kg bodyweight. There was no sign of reaction to treatment.

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There was no death

Clinical signs:

other: There was no systemic sign of reaction to treatment. There was no local sign of reaction to treatment at the application site.

Gross pathology:

Necropsy findings were confined to large submandibular lymph nodes in one male animal.

See attached background information for table of necroscopy observations.

Other findings:

- Local signs: There was no local sign of reaction to treatment at the application site.

see attached background information for table of necroscopy observations.

Any other information on results incl. tables

Mortality

Dosage (mg/kg)	Mortality
	Male	Female	Combined
2000	0/0	0/0	0/0

Systemic signs

Signs	Number of animals showing signs+
	Males	Females
No abnormality detected	5	5
Total number of survivors	5	5

 

+ Five animals in each sex group

Local signs

Signs	Number of animals showing signs+
	Males	Females
No abnormality detected	5	5
Total number of survivors	5	5

+ Five animals in each sex group

Applicant's summary and conclusion

Interpretation of results:

other: low percutaneous toxicity

Conclusions:

Under the conditions of this study, the acute percutaneous median lethal dosage (LD50) of the test material was greater than 2000 mg/kg. Accordingly, the test item was assigned to the class 'low percutaneous toxicity'.

Executive summary:

The acute percutaneous toxicity of test item was investigated in a group of five male and five female CD rats according to EU method B3. The test material was applied to the closely-clipped dorsum of each animal at a dosage of 2000 mg/kg bodyweight, and was covered by an occlusive dressing for 24 hours. Mortality, systemic and local signs of reaction to treatment were recorded during a subsequent 14 -day period of observation. The animals were killed on the following day and subjected to necropsy. There was no death. There was no local or systemic sign of reaction to treatment. The animals achieved anticipated bodyweight gains. Necropsy findings were unremarkable. Under the conditions of this study, the acute percutaneous median lethal dosage (LD50) of the test material was greater than 2000 mg/kg. Accordingly, the test item was assigned to the class 'low percutaneous toxicity'.