1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No OECD Guideline study but according to accepted scientific standards at time of performance

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

no

Remarks:

not required at time of testing

Type of study:

Buehler test

Justification for non-LLNA method:

The LLNA was not available at time of study implementation. Existing data from Buehler study scientifically adequate.

Test material

Test material information

Constituent 1

Reference substance name:

Octopirox

IUPAC Name:

Octopirox

Constituent 2

Reference substance name:

Piroctone olamine

IUPAC Name:

Piroctone olamine

Constituent 3

Reference substance name:

1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

EC Number:

272-574-2

EC Name:

1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Cas Number:

68890-66-4

Molecular formula:

C14H23NO2.C2H7NO

IUPAC Name:

1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Constituent 4

Reference substance name:

1-Hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone, 2-aminoethanol salt

IUPAC Name:

1-Hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone, 2-aminoethanol salt

In vitro test system

Details on the study design:

No in vitro test system available at time of study implementation. Available data from Buehler study scientifically adequate.

In chemico test system

Details on the study design:

No in chemico test system available at time of study implementation. Available data from Buehler study scientifically adequate.

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

male

Details on test animals and environmental conditions:

initial body weights 300 - 400 g

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

water

Induction 2

Concentration / amount:

40 %

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

water

Challenge 2

Concentration / amount:

40 %

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: Yes

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 9
- Exposure period: 3 weeks
- Test groups: 1
- Control group: 1
- Site: back skin
- Frequency of applications: 3 per week
- Duration: 6 hours
- Concentrations: 40 %

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Exposure period: 6 hours
- Test groups: 1
- Control group: 1
- Concentrations: 40 %
- Evaluation (hr after challenge): 24, 48

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

40%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 40%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

40%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 40%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Octopirox is not a skin sensitiser in the Buehler test

Executive summary:

Possible skin sensitizing properties of Octopirox were evaluated in Pirbright White guinea pigs using the method of Buehler. Since test concentrations of 40% were tolerated by the guinea pigs without signs of irritation and higher concentrations were too viscous for application, induction exposure and challenge treatment were performed with the 40% concentration of the test substance. For induction exposure 0.5 mL of the 40% dilution was percutaneously applied 9 times in 3 weeks to the intact dorsal skin of 10 male guinea pigs in an occlusive patch test. Exposure was 6 hours on the days of treatment. After the last application, the animals remained untreated for 14 days. Subsequent to this rest period, challenge treatment was carried out by application of 0.5 mL of the 40% dilution under an occlusive patch for 6 hours. During the induction phase marked signs of irritation occurred which, however, were completely reversible within the recovery period. Challenge treatment with 0.5 mL of the 40% dilution caused no signs of irritation in any guinea pig. In addition, the 5 non-sensitized control animals also showed no dermal reactions following challenge treatment. Thus, testing for dermal sensitization with Octopirox in the guinea pig caused no hypersensitive reactions. Octopirox is not regarded to be a skin sensitizer.