Pidolic acid

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 January 2017 - 02 February 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 22 July 2010

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Pidolic acid

EC Number:

202-700-3

EC Name:

Pidolic acid

Cas Number:

98-79-3

Molecular formula:

C5H7NO3

IUPAC Name:

5-oxo-L-proline

Test material form:

solid: particulate/powder

Details on test material:

white solid crystalline powder

Specific details on test material used for the study:

Batch number: 20140124
Physical state/Appearance: white crystalline solid
Storage Conditions: room temperature in the dark

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Remarks:

CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

The animals were nulliparous and non-pregnant. After an acclimatization period of at least 5 days the animals were selected at random and given a number unique within the study by indelible ink marking on the tail and a number written on a cage card. At the start of the study the animals were in the weight range of 15 to 23 g, and were 8 to 12 weeks old.

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

25%, 10% or 5% w/w in dimethyl formamide

No. of animals per dose:

Groups of four mice/dose

Positive control substance(s):

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

Results and discussion

Positive control results:

α-Hexylcinnamaldehyde, tech., 85% was considered to be a sensitizer under the conditions of the test.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

1.08

Test group / Remarks:

5% w/w

Results 2

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

10% w/w

Results 3

Key result

Parameter:

SI

Value:

1.38

Test group / Remarks:

25% w/w

Any other information on results incl. tables

There were no deaths. No signs of systemic toxicity were noted in the test or control animals during the test. Body weight change of the test animals between Day 1 and Day 6 was comparable to that observed in the corresponding control group animals over the same period.

Applicant's summary and conclusion

Conclusions:

The substance was considered to be a non-sensitizer under the conditions of the test.

Executive summary:

A study was performed to assess the skin sensitization potential of the substance in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear. Three groups, each of four animals, were treated with 50 μL (25 μL per ear) of the substance as a solution in dimethyl formamide at concentrations of 25%, 10% or 5% w/w. A further group of four animals was treated with dimethyl formamide alone. The Stimulation Index at concentrations of 25%, 10% or 5% w/w was 1.08, 1.00 and 1.38, respectively. Therefore, the substance was considered to be a non-sensitizer under the conditions of the test.