2-phenyl-1H-benzimidazole-5-sulphonic acid

Specific investigations: other studies

Link to relevant study record(s)

Reference

Endpoint:

phototoxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 - 18 Apr 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: scientifically valid method with positive control, sufficient documentation

Qualifier:

no guideline available

Principles of method if other than guideline:

Phototoxicity study in guinea pigs according to the method of Vinson and Borselli (J. Soc. Cosm. Chem., 17, 123-130, 1966) modified by the test facility

GLP compliance:

yes (incl. QA statement)

Remarks:

Bezirksregierung Lüneburg, Germany

Type of method:

in vivo

Endpoint addressed:

skin irritation / corrosion

Species:

guinea pig

Strain:

other: Pirbright white (Bor:DHPW (SPF))

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Fa. Winkelmann, Borchen, Germany
- Weight at study initiation: 321 - 365 g
- Housing: collective housing up to a maximum of 5 animals per cage (Macrolon type IV); bedding: LIGNOCEL 3/4 Fasern (Rettenmaier&Söhne GmbH + Co., Ellwangen-Holzmühle, Germany)
- Diet: Ssniff-G pellets (Ssniff Spezialdiäten GmbH, Soest, Germany), ad libitum
- Water: drinking water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

dermal

Vehicle:

water

Details on exposure:

TEST SITE
- Area of exposure: back (divided in four separate areas)
Test group:
Area 1: no application, irradiation only
Areas 2 and 3: test substance (50 and 100%) and irradiation
Area 4: positive control substance and irradiation

Control group:
Area 1: no application
Areas 2 and 3: test substance (50 and 100%)
Area 4: positive control substance

- Type of wrap if used: open application
- Time intervals for shavings: 24 h before test substance application

TEST MATERIAL
- Amount applied: 50 µL
- Concentration: 50% and 100% (undiluted)
- Constant volume or concentration used: yes

IRRADIATION
- 30 min after test substance application, the test animals, but not the control animals, were irradiated:
Stage 1 (UVB-light): using "TL 20 W/12" lamps, duration: 50 s, irradiance: 20.6 W/m², radiant exposure: 0.10 J/cm²
Stage 2 (UVA-light): using "TL 20 W/09" lamps equipped with glass filters to eliminate UVB-irradiation, duration: 26 min, irradiance: 65.8 W/m², radiant exposure: 10.26 J/cm²

USE OF RESTRAINERS FOR PREVENTING INGESTION: yes

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

30 min after test substance application (control and test animals) irradiation was performed for 26.83 min (test animals only)

Frequency of treatment:

test substance application and irradiation was performed once

Post exposure period:

Observation period: 48 h
Reading time points of dermal irritation: 24 and 48 h after irradiation

Remarks:

Doses / Concentrations:
50% and 100% (undiluted)
Basis:

No. of animals per sex per dose:

10 test animals (total) with irradiation

Control animals:

other: concurrent test substance treatment of 5 control animals (total) without irradiation

Details on study design:

A range finding study was conducted with four different concentrations of the test substance (10, 25, 50 and 100%). Each concentration was applied for 24 h to a seperate area of skin (ca. 2 cm²) on the shaved back of two animals. The back was left uncovered. Skin reactions were evaluated 24 and 48 h p.a. No skin reactions were observed.

5% solution of CAS 27503-81-7 in 75% aq. ethanol

Examinations:

Dermal irritation was evaluated according to the following sheme:
Erythema: 0 (no reaction), 1 (scattered mild erythema), 2 (moderate and diffuse erythema), 3 (intense erythema and swelling)
Edema: 0 (no edema), 1 (slight edema), 2 (moderate edema), 3 (severe edema)

Positive control:

The positive control 8-Methosypsoralen was dissolved in acetone to give a final concentration of 5%. The areas treated with the positive control substance (area 4) showed a phototoxic reaction only in the irradiated test animals. Three and seven test animals showed scattered mild erythema (score 1) at the 24 and 48 h reading time point, respectively.

Details on results:

Neither in the areas treated with the test substance (areas 2 and 3) nor in the untreated area (area 1 - negative control) any skin reactions were observed. Thus the test substance at the applied concentrations is not phototoxic.

Conclusions:

In a phototoxicity study in guinea pigs no skin reactions were observed in irridiated areas treated with 50% and 100% (undiluted) test substance. Thus, the test substance is not considered to be phototoxic.

Description of key information

The test substance is not considered to be phototoxic.

Additional information

In a phototoxicity study in guinea pigs no skin reactions were observed in irridiated areas treated with 50 % and 100 % (undiluted) test substance. Thus, the test substance is not considered to be phototoxic.