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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 3rd August 1981 to 25th August 1981
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Test method is similar to OECD guideline 406. No GLP study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report date:
1981

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
no
Type of study:
guinea pig maximisation test

Test material

Constituent 1
Chemical structure
Reference substance name:
Silicic acid, aluminum sodium salt, sulfurized
EC Number:
309-928-3
EC Name:
Silicic acid, aluminum sodium salt, sulfurized
Cas Number:
101357-30-6
Molecular formula:
|Na+6-x+y+z (S2•-)y(S3•-)z|[Al6-x Si6+x O24] - SOD Where: 6 ≤ 6-x+y+z ≤ 8 0 ≤ x ≤ 1.2 1 ≤ y+z ≤ 2
IUPAC Name:
Silicic acid, aluminum sodium salt, sulfurized
Details on test material:
- Physical state: a blue powder
- Lot/batch No.: 1

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: D.Hall, Darley Oaks, Burton-on-trent, Staffordshire
- Age at study initiation: young
- Weight at study initiation: 300-500g
- Housing: in groups up to a maximum of five in a thermostatically controlled room
- Diet (e.g. ad libitum): TR2 with added vitamin C, ad libitum
- Water (e.g. ad libitum): tap water containing 0.01% vitamin C, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3ºC
- Photoperiod (hrs dark / hrs light): 14 hours light/10 hours dark per day in every 24 hour cycle

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
-Induction phase, injection:
1.- Without Complete Freund´s Adjuvant: 0.5 g of the test material suspended in 7.5 ml of sterile distilled water (6.25%). This was the maximum concentration that could be injected.
2.- With Complete Freund´s Adjuvant: 5 ml of a 12.5% aqueous suspension of the test material emulsified with 5 ml of Complete Freund´s Adjuvant.
-Induction phase, topical application: a 50% concentration in sterile distilled water
-Challenge phase: 25% and 12.5% concentration in sterile distilled water
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
-Induction phase, injection:
1.- Without Complete Freund´s Adjuvant: 0.5 g of the test material suspended in 7.5 ml of sterile distilled water (6.25%). This was the maximum concentration that could be injected.
2.- With Complete Freund´s Adjuvant: 5 ml of a 12.5% aqueous suspension of the test material emulsified with 5 ml of Complete Freund´s Adjuvant.
-Induction phase, topical application: a 50% concentration in sterile distilled water
-Challenge phase: 25% and 12.5% concentration in sterile distilled water
No. of animals per dose:
20
Details on study design:
RANGE FINDING TESTS:
Before the start of the challenge stage of the study the likely maximum non-irritant concentration of the test substance was determined by a range-finding study in a separate group of animals. Four guinea pigs which had been pretreated with Complete Freund´s Adjuvant were used. An 8 x 5 cm area of skin of both flanks of the selected animals was closely clipped. Four concentrations of the test substance in the chosen vehicle were prepared. Concentrations were 100%, 50%, 25% and 12.5% of the supplied test material. Four patches of 2 x 2 cm Whatman No. 3 filter paper each saturated with a different concentration of the test substance preparation were applied to each animal, two patches to each flank. The patches were covered occlusively and secured by two adhesive bandages in the same way as the induction topical application patch assemblies. The patches were removed after 24 hours. The application sites were examined for signs of redness and swelling 24 and 48 hours after the removal of the patches.

MAIN STUDY
A. INDUCTION EXPOSURE
Intradermal injection: Three pairs of injections were made on either side of the centre of an areea 4 x 6 cm clipped over the shoulder of the animal. A row of three injections was made on each side:
1.- 0.1 ml Complete Freund´s Adjuvant
2.- 0.1 ml of test substance alone
3.- 0.05 ml of test substance emulsified with 0.05 ml of Complete Freund´s Adjuvant.
Topical application: one week after injection the same area was closely clipped. A 4 x 2 cm patch of Whatman No. 3 filter paper was saturated with the prepared test substance and applied to the skin of the clipped area. The patch was secured by an overlapping impermeable plastic 5 cm Blenderm adhesive tape. This was secured by elastic bandage wound around the torso of the animal and left in position for 48 hours.

B. CHALLENGE EXPOSURE
The animals were challenged 2 weeks after the topical induction application. The prepared test substance was applied to a 2 x 2 cm piece of filter paper. The patch was applied and secured for 24 h.
- Evaluation (hr after challenge): 24 h after removal of the patch and 48 h after removal of the patch

Challenge controls:
Challenge control phase: 20 additional guinea pigs were treated in a similar manner to the test animals except that the test sample was only applied at the challenge phase
Positive control substance(s):
no

Results and discussion

In vivo (non-LLNA)

Results
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
25% and 12.5% concentration of the test material
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
No visible reactions
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25% and 12.5% concentration of the test material. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No visible reactions.

Any other information on results incl. tables

No visible reaction was exhibited by any animal in the test or control group when challenged with 25% and 12.5% concentrations of hte test material in sterile distilled water.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
There was no evidence suggesting that the test material acts as a sensitiser in the guinea pig. It would be classified as non-allergenic or as a week (Grade I) sensitiser on the Magnusson and Kligman scale, having a sensitisation rate of 0-8%.
Executive summary:

The aim of this study was to determine the skin sensitisation potential of the test material using the guinea pig maximisation test. The procedure used is that described by B.Magnusson and A.M. Kligman (J. Invt. Derm. 1969 52pp.268 -276) (similar to OECD Guideline 406). Twenty guinea pigs were treated by intradermal injection in the shoulder region in an attempt to induce sensitisation (injection induction phase). 7 days later the potential sensitisation process was boosted by an application of the test material over the injection site (topical application induction phase). The animals were challenged 14 days later by application of the test material to the flank for 24 hours with a 25% and 12.5% concentration of the test material. There was no evidence suggesting that the test material acts as a sensitiser in the guinea pig. It would be classified as non-allergenic or as a week (Grade I) sensitiser on the Magnusson and Kligman scale, having a sensitisation rate of 0-8%.

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