Radia 7838

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 22 - September 03, 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD guidelines and according to GLP principles

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): Radiagreen RA
- Physical state: Yellow to amber liquid
- Analytical purity: Unknown
- Lot/batch No.: OE70125
- Expiration date of the lot/batch: 25 January 2011
- Stability under test conditions: Stable
- Storage condition of test material: In refrigerator (2-8ºC) in the dark

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France
- Age at study initiation: approx. 10 weeks
- Weight at study initiation: 21 - 26 g
- Housing: Individual housing in labeled Macrolon cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.4- 22.9
- Humidity (%): 40 - 79
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

Test substance concentrations of 0%, 25%, 50% or 100%

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: dilutions in dimethylformamide
- Irritation: no
- Lymph node proliferation response: no

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Induction
- Criteria used to consider a positive response: The six monthly reliability check is carried out to check the sensitivity of the test system and the reliability of the experimental techniques.

TREATMENT PREPARATION AND ADMINISTRATION:
In the main study, three groups of five experimental animals (Mouse, CBA strain) were treated with test substance
concentrations of 25%, 50% or 100% on three consecutive days, by open application on the ears (25 μl/ear). Five
vehicle control animals were similarly treated, but with vehicle alone (Dimethyl formamide).
Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the
draining (auricular) lymph nodes were excised.
After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was
expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index (SI) was subsequently calculated for
each group.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

The SI values calculated for the substance concentrations 5, 10 and 25% were 1.3, 1.5 and 5.5 respectively. An EC3 value of 15.6% was calculated using linear interpolation.
The calculated EC3 value was found to be in the acceptable range of 2 and 20%. The results of the 6 monthly HCA reliability checks of the recent years were 7.3, 10.3, 9.5 and 13.1%.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

The SI values calculated for the substance concentrations 25, 50 and 100% were 1.6, 4.4 and 6.3 respectively. These results indicate that the test substance could elicit an SI >= 3. The data showed a dose-response and an EC3 value of 37.5% was calculated.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean DPM/animal values for the experimental groups treated with test substance concentrations 25, 50 and 100% were 969, 2722 and 3876 respectively. The mean DPM/animal value for the vehicle control group was 613.

Any other information on results incl. tables

No skin reactions were observed in any of the animals examined.

Comments:

One animal treated at 100% (no. 20) showed marked body weight loss. Body weights and body weight gain of all other experimental animals remained in the same range as controls over the study period.

One animal treated at 100% (no. 20) showed hunched posture, lethargy, hypothermia and ptosis at Day 6.

No mortality occurred and no symptoms of systemic toxicity were observed in the other animals of the main study.

The DPM value of animal no. 20 treated at 100% was not included in the analysis based on the signs of toxicity observed in this animal.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

Radiagreen RA should be classified as skin sensitizer (Category 1).