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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
No data about GLP

Data source

Reference
Reference Type:
publication
Title:
COMPARISON OF THE LOCAL LYMPH NODE ASSAY WITH THE GUINEA-PIG MAXIMIZATION TEST FOR THE DETECTION OF A RANGE OF CONTACT ALLERGENS
Author:
Basketter, D.A. and Scholes, E.W.
Year:
1992
Bibliographic source:
Fd Chem Toxic. Vol. 30, No. 1, pp. 65-69

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
not specified
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): Propyl paraben
- Analytical purity: > 98%

In vivo test system

Test animals

Species:
mouse
Strain:
other: CBA/Ca
Sex:
not specified
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 8 -12 weeks

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
5, 10 and 25%
No. of animals per dose:
4
Details on study design:
MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Criteria used to consider a positive response: A chemical was regarded as a sensitizer in the LLNA if at least one concentration of the chemical resulted in a three-fold or greater increase in ³HTdR incorporation compared to the control values. Also the data had to be compatible with a biological dose response although an allowance was made, especially at high doses, for either local toxicity or immunological suppression.

TREATMENT PREPARATION AND ADMINISTRATION:
Groups of 4 mice were treated by a daily topical application of 25 µL of each test substance concentration on the dorsal surface of each ear for 3 consecutive days. The negative control group was treated with vehicle only. Four days after the first topical application, all mice were injected intraveniously through the tail vein with 20 µCi [³H]methyl thymidine (³HTdR) in 250 µL phosphate buffered saline (PBS). After 5 h, the mice were killed by carbon dioxide asphyxiation and the draining auricular lymph nodes were excised and pooled for each group. A single cell suspension of lymph node cells was prepared. ³HTdR incorporation was measured by β-scintillation counting.
Positive control substance(s):
mercaptobenzothiazole (CAS No 149-30-4)

Results and discussion

Positive control results:
Stimulation Index:
10% positive control substance: 4.5
25% positive control substance: 4.6
50% positive control substance: 5.5

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Remarks:
proliferation response test/control ratio
Value:
1.3
Test group / Remarks:
5% test item
Remarks on result:
other:
Remarks:
A chemical was regarded as a sensitizer in the LLNA if at least one concentration of the chemical resulted in a three-fold or greater increase in the T/C ration
Key result
Parameter:
SI
Remarks:
proliferation response test/control ratio
Value:
1.6
Test group / Remarks:
10% test item
Remarks on result:
other:
Remarks:
A chemical was regarded as a sensitizer in the LLNA if at least one concentration of the chemical resulted in a three-fold or greater increase in the T/C ration
Key result
Parameter:
SI
Remarks:
proliferation response test/control ratio
Value:
1.3
Test group / Remarks:
25% test item
Remarks on result:
other:
Remarks:
A chemical was regarded as a sensitizer in the LLNA if at least one concentration of the chemical resulted in a three-fold or greater increase in the T/C ration

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: not classified
DSD: not classified