Theophylline

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study (OECD)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Theophylline

EC Number:

200-385-7

EC Name:

Theophylline

Cas Number:

58-55-9

Molecular formula:

C7H8N4O2

IUPAC Name:

1,3-dimethyl-2,3,6,7-tetrahydro-1H-purine-2,6-dione

Details on test material:

- Name of test material (as cited in study report): Theophyllin;
- Analytical purity: not reported.

Test animals

Species:

rabbit

Strain:

Vienna White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeder: Gaukler, Offenbach/Main, Germany;
- Mean weight at study initiation: 3.09 kg; 3.20 kg;
- Housing: single;
- Diet (e.g. ad libitum): KLIBA 341, 4 mm, Klingenthalmuehle AG; Kaiseraugst, Switzerland. About 130 g per animal per day;
- Water (e.g. ad libitum): Tap water, about 250 mL per animal per day;
- Acclimation period: At least 8 days before the beginning of the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C;
- Humidity (%): 30 - 70 %;
- Photoperiod (hrs dark / hrs light): 12h/12h.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipping

Vehicle:

water

Controls:

other: untreated skin sites of the same animal.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): about 0.5 g of the suspension is applied.
- Concentration (if solution): 50 % aqueous formulation (w/w).

VEHICLE
- The test substance is insoluble in water, but because of the natural moisture of the skin, distilled water is used to prepare the suspensions so that the test can be carried out under as physiological conditions as possible.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours; 4 hours after removal of the test patches and 24, 48 and 72 hours after the beginning of application, scoring was performed.

Number of animals:

3 (1 male, 2 females).

Details on study design:

TEST SITE
- Clipping of the fur: at least 15 hours before the beginning of the study.
- Application site: Upper third of the back or flanks.
- Area of exposure: 2.5 cm x 2.5 cm;
- Application volume: The test patch (2.5 cm x 2.5 cm) was covered with an about 0.5 mm layer of the 50 % suspension.
- Type of wrap if used: Test patches were secured in position with a porous dressing of 4 layers of absorbent gauze and porous bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): At the end of the exposure period with lutrol and lutrol/water (1:1).

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Irritant / corrosive response data:

4 hours after removal of the test substance an erythema score of 1 (very slight reddening) was determined in two females. No other signs of irritation were noted.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS