5H-Cyclopenta[h]quinazoline, 6,7,8,9-tetrahydro-7,7,8,9,9-pentamethyl-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 July 2013 and 26 July 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

1

Reference substance name:

(8S)-7,7,8,9,9-pentamethyl-5H,6H,7H,8H,9H-cyclopenta[h]quinazoline

EC Number:

801-093-8

Cas Number:

1315251-11-6

Molecular formula:

C16H22N2

IUPAC Name:

(8S)-7,7,8,9,9-pentamethyl-5H,6H,7H,8H,9H-cyclopenta[h]quinazoline

Test material form:

solid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Leicestershire, UK.
- Age at study initiation: Twelve to twenty weeks old.
- Weight at study initiation: At the start of the study the animals weighed 2.59 to 3.29 kg.
- Housing: The animals were individually housed in suspended cages.
- Diet (e.g. ad libitum): Free access to food (2930C Teklad Global Rabbit diet).
- Water (e.g. ad libitum): Free access to mains drinking water.
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): The temperature was set to achieve limits of 19 to 23°C.
- Humidity (%): The relative humidity was set to achieve limits of 30 to 70%.
- Air changes (per hr): At least fifteen changes per hour.
- Photoperiod (hrs dark / hrs light): Lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5 g of the substance, moistened sufficiently with 0.5 mL of distilled water.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3

Details on study design:

Substance formulation and experimental preparation:
For the purpose of the study the test item was used as supplied.
The absorption of the test item was not determined.

Measurement of pH:
The pH of the test item was determined prior to commencement of the study and found to be as follows:
10% w/w aqueous preparation of the test item: pH 8.7 (immediately) and pH 8.3 (after 10 minutes).

Procedure:
On the day before the test each of a group of three rabbits was clipped free of fur from the dorsal/flank area using veterinary clippers. Only animals with a healthy intact epidermis by gross observation were selected for the study.

On the day of the test a suitable test site was selected on the back of each rabbit. At each test site a quantity of 0.5 g of the test item, moistened sufficiently with 0.5 mL of distilled water, was introduced under a 2.5 cm x 2.5 cm cotton gauze patch. The patch was secured in position with a strip of surgical adhesive tape. To prevent the animals interfering with the patches, the trunk of each rabbit was wrapped in an elasticated corset and the animals were returned to their cages for the duration of the exposure period.

Four hours after application the corset and patches were removed from each animal and any residual test item removed by gentle swabbing with cotton wool soaked in distilled water.

Scoring System:
Immediately following removal of the patches and approximately 1, 24, 48 and 72 hours later, the test sites were examined for evidence of primary irritation and scored according to the following scale:

EVALUATION OF SKIN REACTIONS
Erythema and Eschar Formation
No erythema: 0
Very slight erythema (barely perceptible): 1
Well-defined erythema: 2
Moderate to severe erythema: 3
Severe erythema (beef redness) to eschar formation preventing grading of erythema.: 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 millimetre): 3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure): 4

Any other skin reactions and clinical signs of toxicity, if present, were also recorded.

Individual body weights were recorded on Day 0 (the day of dosing) and at the end of the observation period.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 24 hours

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 1 hour

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: No evidence of erythema/eschar formation at any observation

Results 4

Irritation parameter:

edema score

Basis:

animal:

Remarks:

#1, #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The individual scores for erythema/eschar and edema are given in Table 1.
Very slight erythema was noted at two treated skin sites immediately after patch removal and persisted at one treated skin site one hour after patch removal.
No evidence of skin irritation was noted at one treated skin site during the study.

Other effects:

Individual body weights and body weight change are given in Table 2.
All animals showed expected gain in body weight during the study.

Any other information on results incl. tables

Table 1: Individual Skin Reactions

Skin Reaction	Observation Time (following patch removal)	Individual Scores – Rabbit Number and Sex			Total
		#1 Male	#2 Male	#3 Male
Erythema/Eschar Formation	Immediately	1	1	0	(2)
	1 Hour	1	0	0	(1)
	24 Hours	0	0	0	0
	48 Hours	0	0	0	(0)
	72 Hours	0	0	0	(0)
Oedema Formation	Immediately	0	0	0	(0)
	1 Hour	0	0	0	(0)
	24 Hours	0	0	0	0
	48 Hours	0	0	0	(0)
	72 Hours	0	0	0	0
Sum of 24 and 72-Hour Readings (S): 0
Primary Irritation Index (S/6): 0/6 = 0.0
Classification: NON-IRRITANT

Table 2: Individual Body Weights and Body Weight

Rabbit Number and Sex	Individual Body Weight (kg)		Body Weight Change (kg)
	Day 0	Day 3
#1 Male	2.59	2.71	0.12
#2 Male	2.66	2.73	0.06
#3 Male	3.29	3.37	0.08

Applicant's summary and conclusion

Interpretation of results:

other:

Remarks:

Not a skin irritant in accordance with EU CLP (EC no 1272/2008 and its amendments)

Conclusions:

The substance was classified as non-irritant to rabbit skin based on OECD TG 404.

Executive summary:

The study was performed to assess the irritancy potential of the test item to the skin of the New Zealand White rabbit, according to OECD 404 and GLP principles.

A single 4-hour, semi-occluded application of the substance to the intact skin of three rabbits produced very slight erythema at two treated skin sites up to one hour after dressing removal. No evidence of skin irritation was noted at one treated skin site. Results: The substance produced a primary irritation index of 0.0 and was classified as non-irritant to rabbit skin according to the Draize classification scheme.