P 16513

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Strontium 4-chloro-2-[2-hydroxy-6-sulfonatonaphthalen-1-yl)diazenyl]benzoate

Cas Number:

474814-88-5

Molecular formula:

C17H9ClN2O6SSr

IUPAC Name:

Strontium 4-chloro-2-[2-hydroxy-6-sulfonatonaphthalen-1-yl)diazenyl]benzoate

Test material form:

solid: nanoform, no surface treatment

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

according to guideline

Study design: in vivo (LLNA)

Vehicle:

other: ethanol:deionized water (70+30)

Concentration:

2.5, 5, 10% The highest test concentration which could be achieved with other vehicles such as acetone, olive oil, dimethylformamide, dimethylsulfoxide, methyl ethyl ketone or propylene glycol was below 10 %

No. of animals per dose:

4 females (nulliparous and non-pregnant)

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: 10% suspension in ethanol: deionized water (70+30) (highest technixally applicable concentration)
- Irritation: redness of the ear skin could not be observed because of the colored substance; no severe irritant effects occured
- Lymph node proliferation response: expressed as the number of radioactive disintegrations per minute per lymph node and as the ration of 3HTdR incorporated into lymph mode cells of test lymph nodes relative to that recorded for control lymph nodes (stimulation index)


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method:
- Criteria used to consider a positive response:
A test item is regarded as a sensitizer in the LLNA if the following criteria are fulfilled:
- First, that exposure to at least one concentration of the test item resulted in an incorporation of 3HTdR at least 3-fold or greater than that recorded in control mice, as indicated by a stimulation index.
- Second, that the data are compatible with a conventional dose response, although allowance must be made (especially at high dose concentrations) for ether local toxicity or immunological suppression;

TREATMENT PREPARATION AND ADMINISTRATION:
Each test group of mice was tested topical (epidermal) application to the dorsal surface of each ear lobe (left and right) with different test item concentrations of 2.5, 5 and 10 (w/v) in ethanol: deionized water (70:40). The application volume, 25 Ml, was spread over the entire dorsal surface of each ear lobe once daily for three consecutive days. A further group mice was treated with an equivalent volume of the relevant vehicle alone (control animals).

Five days after the first topical application, all mices were administered with 250Ml of 81.1 MCi/ml 3HTdR (corresponds to 20.3 MCi 3HTdR per mouse) by intravenous injection via a tail vein.
Approximately five hours after treatment with 3HTdR all mice were euthanised by intraperitoneal injection of Na-thiopental.
The draining lymph nodes were rapidly excised and pooled per group (8 nodes per group). Single cell suspensions were prepared, washed with phosphate buffered saline, resuspended in trichloroacetic acid, incubated for 18 h at 4°C; the 3HTdR incorporation was measured on a .beta.-scintillation counter.
TREATMENT PREPARATION AND ADMINISTRATION:

Positive control substance(s):

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

Statistics:

The mean values and standard deviations were calculated on the body weights

Results and discussion

Positive control results:

vehicle: acetone:olive oil (4+1)
test item concentration DPM per lymph node S.I.
5% 868.4 1.29
10% 2037.8 3.03
25% 4251.3 6.32

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.44

Test group / Remarks:

2.5 % (w/v)

Results 2

Parameter:

SI

Value:

1.73

Test group / Remarks:

5 % (w/v)

Results 3

Parameter:

SI

Value:

0.76

Test group / Remarks:

10 % (w/v)

Results 4

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: DPM per lymph node: control group: 299.7 2.5 % (w/v): 431.8 5 % (w/v): 517.3 10 % (w/v): 227.1

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Substance not subject of classification and labeling