Bis(D-gluconato-O1,O2)zinc

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

1

Reference substance name:

Zinc sulphate

EC Number:

231-793-3

EC Name:

Zinc sulphate

Cas Number:

7733-02-0

Molecular formula:

H2O4S.Zn

IUPAC Name:

Zinc sulphate

Test material form:

solid: particulate/powder

In vivo test system

Test animals

Species:

mouse

Strain:

Balb/c

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: 6-8 wk

Study design: in vivo (LLNA)

Vehicle:

other: 20 % ethanol

Concentration:

10 % test material in 20 % ethanol solution

No. of animals per dose:

3

Details on study design:

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay (LLNA)
- Criteria used to consider a positive response: Stimulation index ≥ 3

TREATMENT PREPARATION AND ADMINISTRATION:
25 µL of test material was applied to the dorsum of both ears for three consecutive days. Prior to the test material treatment, the ears of each mouse were gently abraded using a 19 g needle. Four days following the initial application, draining lymph nodes were excised.

Preparation of cell suspension:
A single cell suspension of LNC was prepared by mechanical disaggregation through sterile 200 mesh steel gauge. The cells were washed twice with an excess phosphate-buffered saline (PBS) and resuspended in RPMI-1640 culture medium supplemented with 10 % fetal calf serum (FCS), 25 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (Hepes), 100 µg/mL penicillin and 100 U/mL streptomycin. The cell concentration was adjusted to give 5 x 10E6 cells/mL.
Lymphocyte suspensions were seeded into 96 well microtiter plates at a concentration of 1 x 10E6 cells/well (5 wells per animal), and cultured with 0.5 µCi [3H] methyl thymidine ([3H]TdR) for 18 h at 37 °C in a humidified atmosphere of 5 % CO2 in air.
The incorporation of [3H]TdR was measured using a liquid scintillation counter and expressed as mean counts per min (cpm) ± standard deviation per node of three animals for each test group.

Other: Compound solubility - Completely dissolved in 20 % ethanol solution

Statistics:

Not reported

Results and discussion

Positive control results:

Not reported

In vivo (LLNA)

Results

Parameter:

SI

Value:

1.41

Test group / Remarks:

10 % zinc sulfate

Any other information on results incl. tables

Disintegrations per minute (DPM): Mean value cpm ± SD ( x 10-3) = 2.14 ± 0.77

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the test, the test material was determined to be non-sensitising to mice.

Executive summary:

A study was conducted to evaluate the skin sensitisation potential of the test material in mouse using a modified Local Lymph Node Assay. No guideline or GLP compliance was documented in the study report.

Groups of BALB/c mice (n=3) were treated with 10% concentration of test material or vehicle (20% ethanol solution) by applying 25 µL to the dorsum of both abraded ears for three consecutive days. Four days following the initial application, draining lymph nodes were excised. A single cell suspension of LNC was prepared and the incorporation of [3H]TdR was measured using a liquid scintillation counter.

[3H]TdR incorporation (expressed as mean counts per min (cpm) ± standard deviation per node x 10-3) was 2.14 ± 0.77 and the ratio of the proliferation in treated group to that in vehicle control (stimulation index) was 1.41.

Hence, under the conditions of the test, the test material was determined to be non-sensitising to mice.