Pregna-5,7-diene-3,20-dione, cyclic 3,20-bis(1,2-ethanediyl acetal), (9.beta.,10.alpha.)-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-Jan-1992 to 11-Mar-1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Performed to OECD test guideline and GLP compliant.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

Due to a malfunction of a thermohygrograph the temperature and the relative humidity in the animal room were not recorded on two dates. This deviation was not considered to have affected the integrity of the study performed.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(9R,10S,13S)-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)spiro[1,2,4,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,2'-1,3-dioxolane]

EC Number:

611-207-6

Cas Number:

5488-51-7

Molecular formula:

C25H36O4

IUPAC Name:

(9R,10S,13S)-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)spiro[1,2,4,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,2'-1,3-dioxolane]

Test material form:

solid: crystalline

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

SPF-derived male New Zealand White rabbits (2.5-3.0 kg) were obtained from Harlan Olac, Zeist, The Netherlands. The animals were inspected for signs of illness at the beginning of the acclimatization period. No abnormalities were detected.

Animal care
Three rabbits were individually housed in stainless steel wire cages KK 102. Sawdust, woodchips, or other extraneous material that might produce skin irritation were excluded. The rabbits received 80 g food (a standard laboratory diet LKK-20, Hope Farms, Woerden, The Netherlands) per day during the acclimatization period of 5 days. During the experiment the animals had free access to food and water. Animals were housed in room no. 301, CDA Ill with the following animal room conditions:
Temperature 18-20'C;
Relative humidity 60-74%;
Artificial light from 7 a.m. till 7 p.m.;
Radio-sound on 12 hours per day;
Ventilation approximately 16 air changes per hour.

Treatment
The test procedure used was in accordance with OECD guideline 404, adopted on 12 May 1981. On the last day of the acclimatization period the backs of the three rabbits were clipped free of hair. A 6 cm2 patch was prepared, 0.5 g of the test material was applied and was moistioned with 0.5 ml water. The patch was sustained by occlusive Blenderm tape and secured in place on the back of the animal by adhesive tape. The animals were fitted with Elizabethan collars (IMS, Cheshire, UK) in order to prevent disturbance of the application for 4 hours. After this period the collars and patches were removed and the skin was wiped to remove any remaining test substance.

At 30-60 minutes and at 24, 48 and 72 hours after patch removal, the skin reactions caused by the test substance were scored.

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Amount / concentration applied:

A 6 cm2 patch was prepared, 0.5 g of the test material was applied and was moistioned with 0.5 ml water. The patch was sustained by occlusive Blenderm tape and secured in place on the back of the animal by adhesive tape.

Duration of treatment / exposure:

The animals were fitted with Elizabethan collars (IMS, Cheshire, UK) in order to prevent disturbance of the application for 4 hours. After this period the collars and patches were removed and the skin was wiped to remove any remaining test substance.

Observation period:

At 30-60 minutes and at 24, 48 and 72 hours after patch removal, the skin reactions caused by the test substance were scored.

Number of animals:

3 males

Details on study design:

TEST SITE
- Area of exposure: A 6 cm2 patch was prepared, 0.5 g of the test material was applied and was moistioned with 0.5 ml water.
- Type of wrap if used: The patch was sustained by occlusive Blenderm tape and secured in place on the back of the animal by adhesive tape.
REMOVAL OF TEST SUBSTANCE
The patch was sustained by occlusive Blenderm tape and secured in place on the back of the animal by adhesive tape. The animals were fitted
with Elizabethan collars (IMS, Cheshire, UK) in order to prevent disturbance of the application for 4 hours. After this period the collars and patches were removed and the skin was wiped to remove any remaining test substance.

SCORING SYSTEM:
Evaluation of skin reactions

At 30-60 minutes and at 24, 48 and 72 hours after patch removal, the skin reactions caused by the test substance were scored on the basis of the grades described in the following table.

Erythema and eschar formation Grade
No erythema 0
Very slight erythema (barely perceptable) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) to slight eschar formation (injuries in depth) 4

Oedema formation
No oedema 0
Very slight oedema (barely perceptable) 1
Slight oedema (edges of area well defined by definite raising) 2
Moderate oedema (raised approximately 1 mm) 3
Severe oedema (raised more than 1 mm and extending
beyond area of exposure) 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Retroketal is considered to cause no skin irritation in rabbits. The test material is therefore classified as non-irritant according to EEC labelling regulations. No symbol and no risk phrase are required.