Acetoacetanilide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP and OECD guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

a) an additional validation/pos. control GLP study was performed b) relative humidity in the animal room was between approximately 30 - 83 %.. These deviations did not affect the validity of the study.

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Acetoacetanilide

EC Number:

202-996-4

EC Name:

Acetoacetanilide

Cas Number:

102-01-2

Molecular formula:

C10H11NO2

IUPAC Name:

3-oxo-N-phenylbutanamide

Details on test material:

- Name of test material (as cited in study report): Acetoacet-Anilide

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

- Source: Harlan Netherlands BV Postbus 6174, NL - 5960 AD Horst
- Age: 8 - 12 weeks
- Housing: single caging
- Identification: by cage number
- Feed: pelleted standard diet, ad libitum
- Temperature: 22 +/- 3°C
- Relative humidity: 30-83%
- Light: artificial light 6 a.m. - 6 p.m.

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

10, 25, 50 % (w/v)

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: stable in dry DMF for more than 72hrs
- Irritation: no irritation effects were observed after a single application of the test item

MAIN STUDY
- Criteria used to consider a positive response: Stimulation index of more than 3

Positive control substance(s):

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

Statistics:

A statistical analysis was conducted for assessment of the dose-response relationship, and the EC3 value was calculated according to the equation
EC3 = (a-c) [(3-d)/(b-d)] + c
where EC3 is the estimated concentration of the test item required to produce a 3-fold increase in draining lymph node cell proliferative activity; (a, b) and (c, d) are respectively the co-ordinates of the two pair of data lying immediately above and below the S.I. value of 3 on the local lymph node assay dose response plot.

Results and discussion

Positive control results:

Results of the Positive Control Study performed in April 2004: EC3 = (a-c) [(3-d)/(b-d)] + c = 6.3% (w/v)
Results of the Positive Control GLP Study performed in October 2004: EC3 = (a-c) [(3-d)/(b-d)] + c = 9.9 % (w/v)

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: 10%: 1.2 25%: 1.3 50%: 2.3

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: DPM per lymph node: 10%: 47.1 25%: 50.9 50%: 91.7 Control: 39.5

Any other information on results incl. tables

Viability / Mortality

No deaths occurred during the study period.

Clinical Signs

After the first application the animals did not show any clinical signs of toxicity.

At the lowest concentration (10%) no symptoms of local toxicity at the ears of the animals were observed up to the third day of application.

At the mid dose (25%) the ear skin of two animals was inflamed after second and three animals after the third application.

After the second application onwards the highest dose (50%) induced inflamed ear skin at all the four animals of the group.

Body Weights

The body weight of the animals, recorded prior to the 1st application and prior to necropsy, was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item Acetoacet-Anilide was found to be not a skin sensitiser in this assay.

Executive summary:

In the study the test item Acetoacet-Anilide dissolved in DMF was assessed for its possible contact allergenic potential.

For this purpose a local lymph node assay was performed using test item concentrations of 10%, 25%, and 50%.

After the first application the animals did not show any clinical signs of toxicity. After the second application onwards the highest dose (50%) induced inflamed ear skin at all the four animals of the group. At the mid dose of 25% the ear skin of two animals was inflamed after second and at three animals after the third application.

All treated animals survived the scheduled study period.

In this study Stimulation Indices (S.I.) of 1.2, 1.3, and 2.3 were determined with the test item at concentrations of 10, 25, and 50% (w/v) in DMF.

The test item Acetoacet-Anilide was found to be not a skin sensitiser in this assay.