4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed journal

Data source

Reference

Reference Type:

publication

Title:

Final Report on the Safety Assessment of Phenyl Methyl Pyrazolone

Author:

Cosmetic Ingredient Expert Review Panel

Year:

1992

Bibliographic source:

JOURNAL OF THE AMERICAN COLLEGE OF TOXICOLOGY Volume 11, Number 4,1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

Skin sensitization study of3-Methyl-1-Phenyl-5-Pyrazolone (CAS no: 89-25-8) was conducted on 20 guinea pigs to assess its skin sensitization potential.

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-1-phenyl-5-pyrazolone

EC Number:

201-891-0

EC Name:

3-methyl-1-phenyl-5-pyrazolone

Cas Number:

89-25-8

Molecular formula:

C10H10N2O

IUPAC Name:

1-Phenyl-3-methyl-5-pyrazolone

Test material form:

solid

Details on test material:

- Name of test material (as cited in study report): Phenyl methyl pyrazolone (PMP)
- Molecular formula :C10H10N2O
- Molecular weight :174.2g/mole
- Substance type:organic
- Physical state: solid

Specific details on test material used for the study:

- Name of test material (as cited in study report): Phenyl methyl pyrazolone (PMP)
- Molecular formula :C10H10N2O
- Molecular weight :174.2g/mole
- Substance type:organic
- Physical state: solid

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: albino

Sex:

male/female

Details on test animals and environmental conditions:

No data available

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

Epicutaneous concentration: 0.50 ml of PMP, a 0.5% in (w/w) water.

Intradermal concentration: 0.1ml3 freund’s complete adjuvant diluted to 50% with sterile isotonic saline.

Day(s)/duration:

3 weeks

Adequacy of induction:

not specified

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

0.5 ml

Day(s)/duration:

48 hours

Adequacy of challenge:

not specified

No. of animals per dose:

Total :20
Male :10
Female:10

Details on study design:

Details on study design
RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures:10
- Exposure period:1hr
- Test groups:20
- Control group:No data available
- Site: clipped skin of left scapular region
- Frequency of applications:3 times in week
- Duration:3 weeks
- Concentrations: Epicutaneous concentration: 0.50 ml of PMP, a 0.5% in (w/w) water.

Intradermal concentration: 0.1ml3 freund’s complete adjuvant diluted to 50% with sterile isotonic saline.

B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge:After 12 days rest period
- Exposure period:1hr
- Test groups:20
- Control group:
- Site: clipped skin of left flank of abdomen
- Concentrations:0.5 ml
- Evaluation (hr after challenge):1, 6, 24, 48 hrs.

OTHER: After removal of patch, the test site was rinsed with water.

Challenge controls:

No data available

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.5 ml

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Skin sensitization reactions were not observed

Remarks on result:

no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:

other: Not Sensitizing

Conclusions:

The test material 3-Methyl-1-Phenyl-5-Pyrazolonewas (CAS No:-89-25-8) was considered to be not sensitizing to the skin of albino guinea pigs under occlusive condition.

Executive summary:

Skin sensitization study of 3-Methyl-1-Phenyl-5-Pyrazolone(CAS no: 89-25-8) was conducted on 20 guinea pigs to assess its skin sensitization potential.

 

In induction phase, 0.5ml of a 0.5% aqueous 3-methyl-1-phenyl-5-pyrazolone solution was applied dermally onclipped skin of left scapular regionfor 1hr under occlusive condition. This procedure was repeated 3 times in week for total 10 applications. After removal of patch the test site was rinsed with water. During the study, the guinea pigs received 2 intradermal injections of 0.1ml³freund’s complete adjuvant diluted to 50% with sterile isotonic saline near the test site.

 

After 12 days rest period, animals were challenged at concentration of 0.50ml on clipped skin of left flank of abdomen using occlusive patch for 1 hour. After removal of patch, skin site was rinsed and observations were made after 1, 6, 24, 48 hrs.

 

None of the animal produced any skin reactions at challenge concentration .Hence, 3-Methyl-1-Phenyl-5-Pyrazolonewas (CAS No:-89-25-8) was considered to be not sensitizing to the skin of albino guinea pigs.