5,7-di-tert-butyl-3-[4-(2-hydroxyethoxy)phenyl]-1-heteropolycycl-2(3H)-one

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31 July 2013 - 14 August 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

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

Principles of method if other than guideline:

On occasions, the humidity was outside the target range of 30 - 70 %. This was not felt to have affected the validity of the study.

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Storage condition of test material: Room temperature in the dark.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain: RccHanTM:WIST
- Age at study initiation: 8 to 12 weeks old.
- Weight at study initiation: Animals weighed at least 200 g. The weight variation did not exceed ± 20 % of the mean weight for each sex. Males: 272 - 313 g, Females: 221 - 245 g
- Housing: Individually in suspended solid floor polypropylene cages during the exposure period, and then in groups of 5 per sex for the reminder of the study.
- Diet: Rodent diet available ad libitum.
- Water: drinking water available ad libitum.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25 °C
- Humidity (%): 30 to 70 %
- Air changes (per hr): At least fifteen changes per hour.
- Photoperiod (hrs dark / hrs light): Twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.
- Other: Animals provided with environmental enrichment items which did not contain any contaminant at a level that might affect the purpose or integrity of the study.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

arachis oil

Details on dermal exposure:

TEST SITE
- Area of exposure: The backs and flanks of each animal (clipped).
- % coverage: Approximately 10 % of the total body surface area.
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing: After removal of the bandage, the test site was wiped free of any excess test material using cotton wool moistened with arachis oil BP.
- Time after start of exposure: 24 hours.

TEST MATERIAL
- Amount applied: The test material was weighed out according to each animal's individual body weight.
- Application: An appropriate amount of the test material was moistened with arachis oil BP prior to application.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 male and 5 female per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing: The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.
After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation and scored according to the following the Draize (1977) scale, see Table 1. Any other skin reactions, if present were also recorded.
Individual body weights were recorded prior to application of the test material on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: Yes, at the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Statistics:

Data evaluations included the relationship, if any, between the exposure of the animal to the test material and the incidence and severity of all abnormalities including behavioral and clinical observations, gross lesions, body weight changes, mortality and any other toxicological effects.
Using the mortality data obtained, an estimate of the acute dermal median lethal dose (LD50) of the test item was made.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths.

Clinical signs:

other: Clinical Signs: There were no signs of systemic toxicity.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

Dermal Irritation: See tables 2 and 3.
Males: There were no signs of dermal irritation noted at the test site of one male. Very slight erythema (grade 1) was noted at the test sites of four males which persisted from 1 to 7 days post exposure.
Females: Well-defined erythema (grade 1 or 2) and very slight edema (grade 1) were noted at the test sites of all females. Erythema was observed from 1 day post exposure and persisted in 2 animals up to 13 days. Edemas were observed for the first 2 days only.
Other signs of dermal irritation noted at the test sites of females were crust formation, small superficial scattered scabs and scab lifting to reveal glossy skin. These observations were first noted on day 5 and persisted until termination on day 14.

Any other information on results incl. tables

Table 2: Male Local Reactions

Dose Level (mg/kg)	Animal No.	Observation	Days After Exposure
			1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	1-0	Erythema	1	1	1	1	1	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-1	Erythema	1	1	1	1	1	1	1	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-2	Erythema	1	1	1	1	1	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-3	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-4	Erythema	1	1	1	1	1	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0 = No reaction

Table 3: Female Local Reactions

Dose Level (mg/kg)	Animal No.	Observation	Days After Exposure
			1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	2-0	Erythema	2	2	1	1	1	1	1	0	0	0	0	0	0	0
		Edema	1	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	Cf	Cf	Cf	0	0	0	0	0	0	0
	2-1	Erythema	2	2	1	1	1	1	1	0	0	0	0	0	0	0
		Edema	1	1	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	Cf, Sg	Cf, Ss	Cf, Ss	Ss	Ss	Ss	Ss	Ss	Ss	Ss
	2-2	Erythema	2	2	2	2	2	2	2	1	1	1	1	1	1	0
		Edema	1	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	Cf, Sg	Cf, Sg	Cf, Sg	Ss, Sg	Ss, Sg	Ss, Sg	Ss, Sg	Ss, Sg	Ss, Sg	Ss
	2-3	Erythema	2	2	2	2	1	1	1	1	1	1	1	1	1	0
		Edema	1	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	0-4	Erythema	2	1	1	1	1	1	1	0	0	0	0	0	0	0
		Edema	1	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0 = No reaction

Cf = Crust Formation

Ss = Small superficial scabs

Sg = Cabs lifting to reveal glossy skin

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the test, no mortality or systemic signs of toxicity were observed. Therefore the LD50 was determined to be > 2000 mg/kg bw. Furthermore only mild local irritation was observed at the test site.

Executive summary:

The acute toxicity of the test material was determined via the dermal route using male and female Wistar rats in a study performed under GLP conditions and in accordance with the standardised guidelines OECD 402 and EU Method B3.

A group of ten animals (five males and five females) was given a single, 24 hour, semi-occluded dermal application of the test item to intact skin at a dose level of 2000 mg/kg body weight. Mortality, clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

Under the conditions of the test no mortality or systemic signs of toxicity were observed. Animals displayed overall expected weight gain and no abnormalities were observed at necropsy. There were no signs of dermal irritation noted at the test site of one male. Very slight erythema was noted at the test sites of four males. Well-defined erythema and very slight edema were noted at the test sites of all females. Other signs of dermal irritation noted at the test sites of females were crust formation, small superficial scattered scabs and scab lifting to reveal glossy skin. Based on these observations the LD50 was determined to be > 2000 mg/kg bw.