1-imino-1H-isoindol-3-amine

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-06-12 to 2017-07-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The test for acute dermal toxicity is performed on the rat. Although several mammalian species may be used, the rat is the preferred rodent species.
In the assessment and evaluation of the toxic characteristics of chemicals, the determination of acute dermal toxicity is useful where exposure by the dermal route is likely.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1-imino-1H-isoindol-3-amine

EC Number:

222-426-8

EC Name:

1-imino-1H-isoindol-3-amine

Cas Number:

3468-11-9

Molecular formula:

C8H7N3

IUPAC Name:

1-imino-1H-isoindol-3-amine

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Crl: WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test animals:
Source: Charles River, 97633 Sulzfeld, Germany
Sex: male and female (non-pregnant and nulliparous)
Number of animals: 5 male and 5 female animals
Age at the beginning of the study: males: 11-12 weeks; females: 12-13 weeks
Body weight on the day of administration:Males: 276g - 304g; Females: 218g - 230g

Housing and Feeding Conditions:
- Full barrier in an air-conditioned room
- Temperature: 22 ± 3 °C
- Relative humidity: 55 ± 10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice
- Free access to tap water, sulphur acidified to a pH value of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- The animals were kept individually in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding
- Adequate acclimatisation period (at least five days) under laboratory conditions

Administration / exposure

Type of coverage:

occlusive

Vehicle:

water

Details on dermal exposure:

Preparation of the Animals:
- The animals were marked individualy by tail painting
- Approx. 24 hours before the test, the fur was removed from the dorsal area of the trunk using an electric clipper. Only animals with healthy intact skin were used
- Prior to the application a detailed clinical observation was performed on all animals. Only healthy animals were used.

Application:
- The test item was applied at a single dose, uniformly over an area which was approximately 10% of the total body surface
- The test item was held in contact with the skin by a dressing throughout a 24-hour period. The dressing consisted of a gauze-dressing and non-irritating tape and was fixed with an additional dressing in a suitable manner

Dose Level:
- The test item was applied at a single dose of 2000 mg/kg body weight to each animal

Exposure Period:
- The test item was held in contact with the skin throughout a 24-hour period. At the end of the exposure period the residual test item was removed using aqua ad injectionem

Duration of exposure:

24 h

Doses:

a single dose of 2000 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

Observation Period:
- All animals were observed for 14 days after dosing

Evaluation of Primary Skin Irritation:
- Signs of erythema and oedema were assessed using the scoring system laid down in OECD Guideline 404

Weight Assessment:
The animals were weighed on day 1 (prior to the application) and on days 8 and 15

Clinical Examination:
- A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose)
- As soon as symptoms were noticed they were recorded
- Thereafter the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded
- Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Attention was directed to observations of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma

Pathology:
- At the end of the observation period the animals were sacrificed with an overdosage of pentobarbital injected intraperitoneally at a dosage of 250-400 mg/kg bw
- All animals were subjected to gross necropsy and examined macroscopically for gross pathological changes
- In absence of gross pathological changes no tissues were preserved for a possible histopathological evaluation

Evaluation of Results:
- Individual reactions of each animal were recorded at each time of observation
- Toxic response data were recorded by sex and dose level
- Nature, severity and duration of clinical observations were described
- The body weight changes were summarised in a tabular form
- Necropsy findings were described

Statistics:

not specified

Results and discussion

Preliminary study:

not applicable

Effect levels

Effect levels 1

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: skin irritation reported

Effect levels 2

Sex:

male

Dose descriptor:

other: dose

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortality

Effect levels 3

Sex:

female

Dose descriptor:

other: dose

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortality

Mortality:

The test item showed no mortality

Clinical signs:

other: No signs of systemic toxicity. Signs of local toxicity and irritation.

Gross pathology:

No specific gross pathological changes were recorded for any animal

Other findings:

- Erythema grade 1 was observed in all male animals but no female animals
- Crust was observed in 4 of 5 male and all female animals
- Necrosis was observed in 3 of 5 male animals but in no female animals
- Necrosis was not reversible within the observation period

Any other information on results incl. tables

Absolute body weights in g and body weight gain in %

Animal No. / Sex	body weight gain (g)			%
	Day 1	Day 8	Day 15	Day 1-15
21/Male	286	271	307	7
22/Male	304	315	349	15
23/Male	279	295	327	17
24/Male	276	283	304	10
25/Male	287	291	316	10
26/Female	219	216	215	-2
27/Female	218	224	230	6
28/Female	229	227	245	7
29/Female	230	240	240	4
30/Female	223	224	230	3

The effects on weight loss are a common observation for animals within this study type, mainly for female animals and might be secondary to the dressing, and toxicological relevance of this finding cannot clearly be concluded.

 LD₅₀Cut-Off

Dose (mg/kg bw)		Number of Animals		Number of Intercurrent Deaths		LD50Cut-Off (mg/kg bw)
2000		5 males		0		> 2000
2000		5 females		0		> 2000

bw = body weight

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal lethal dose of the test item after a single dermal administration to female rats, observed over a period of 14 days is: LD50 cut-off (rat) > 2000 mg/kg bw.

Executive summary:

In order to determine the potential acute dermal toxicity of the test item, an acute dermal study on the rat was performed according to OECD 402 and in compliance to GLP. Wistar rats (5 male and 5 female) were exposed for 24h to 2000 mg/kg bw test substance.

Single dermal application of the test item to rats at a dose of 2000 mg/kg body weight was not associated with mortality but with signs of local toxicity and irritation were observed. Although weight loss effects were observed, especially with female animals, it is concluded that this is a common observation for this study type and that this is probably secondary to the dressing. Toxicological relevance of this finding cannot be clearly concluded.

In conclusion, the dermal LD₅₀was determined to be > 2000 mg/kg body weight.