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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
27.03.1995 to 05.05.1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP. The study is a read across from the ammonium salt (CAS 34274-28-7).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes (incl. certificate)
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): AMGARD RD1
- Substance type: Phosphonic acid (ammonium salt of ATMP)
- Physical state: Straw coloured liquid
- Analytical purity: No data
- Impurities (identity and concentrations): No data
- Purity test date: No data
- Lot/batch No.: 20.2.95
- Expiration date of the lot/batch: No data
- Stability under test conditions: No data
- Storage condition of test material: Room temperature

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: David Hall Limited, Staffordshire, UK.
- Age at study initiation:8-12 weeks
- Weight at study initiation: 334-430 g
- Housing: Singly or in pairs in solid-floor polypropylene cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Minimum five days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-28
- Humidity (%): 51-68
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 27.03.1995 To 05.05.1995

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
Intradermal induction: 10% w/v in distilled water; 10% w/v in a mixture of FCA plus distilled water (1:1).
Topical induction: undiluted.
Topical challenge: 100% and 75% v/v in distilled water.
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
Intradermal induction: 10% w/v in distilled water; 10% w/v in a mixture of FCA plus distilled water (1:1).
Topical induction: undiluted.
Topical challenge: 100% and 75% v/v in distilled water.
No. of animals per dose:
20 test and 10 control used for the main study.
Details on study design:
RANGE FINDING TESTS: Four concentrations of test substance were investigated (1, 5, 10 and 25% w/v in distilled water). A total of four guinea pigs were used, each animal received four 0.1 ml injections of only one concentration of the test substance. The degree of erythema at the injection sites was assessed approximately 24, 48 and 72 hours and seven days after the injection according to the Draize scale. Oedema was not assessed. Evidence of systemic toxicity was recorded. The highest concentration that caused only mild to moderate skin irritation, and which was well tolerated systemically, was selected for the intradermal induction stage of the main study.
Two guinea pigs (intradermally injected with Freund's Complete Adjuvant 15 days earlier) were treated with the undiluted test substance and three preparations of the test substance (75, 50 and 25%) v/v in distilled water). Applications were made to the clipped flanks under occlusive dressings for an exposure period of 48 hours.The degree of erythema and oedema was evaluated approximately 1, 24 and 48 hours after dressing removal. The highest concentration producing only mild to moderate dermal irritation was selected for the topical induction stage of the main study.
The undiluted test substance and three preparations of the test substance (75, 50 and 25% v/v in distilled water) were applied to the clipped flanks of two guinea pigs under occlusive dressings for 24 hours. The animals did not form part of the main study, but had been treated identically to the controls of the main study up to Day 14. The degree of erythema and oedema was evaluated approximately 1, 24 and 48 hours after dressing removal. The highest non-irritant concentration of test substance and one lower concentration were selected for the topical challenge stage of the main study.
MAIN STUDY
A. INDUCTION EXPOSURE
Shortly before treatment on Day 0 the hair was removed from an area on the shoulder region of each animal. A row of three injections (0.1ml) each was made on each side of the mid-line. The injections were: a) FCA plus distilled water (1:1); b) a 10% w/v formulation of the test substance in distilled water; c) a 10% w/v formulation of the test substance in a 1:1 preparation of FCA plus distilled water. Approximately 24 and 48 hours after the intradermal injection, the degree of erythema at the injection sites was evaluated. One week later (Day 7), the same area on the shoulder region was clipped again and treated with a topical application of the undiluted test substance (under an occlusive dressing for 48 hours). The degree of erythema and oedema was quantified at one and 24 hours following removal of the patches.
Induction of the control animals used an identical procedure as the test animals, except the injections were: a) FCA plus distilled water in the ratio 1:1; b) distilled water; c) 50% w/v formulation of distilled water in a 1:1 mixture of FCA/distilled water. The topical applications followed the same procedure as for the test animals, but nothing was applied to the patch. Skin reactions were quantified.

B. CHALLENGE EXPOSURE
Shortly before treatment on Day 21, an area of skin on both flanks of each animal was clipped free of hair. A square filter paper patch saturated with the undiluted test substance was applied to the shorn right flank of each animal and was held in place with a strip of surgical adhesive tape. To ensure that the maximum non-irritant concentration was used at challenge, the test substance at a concentration of 75% v/v in distilled water was similarly applied to a skin site on the left shorn flank. The patched were covered with an occlusive dressing. After 24 hours the dressing was removed. The challenge sites were swabbed with cotton wool soaked in distilled water to remove residual material. Prior to the observation period, the flanks were clipped to remove regrown hair.
Approximately 24 and 48 hours after challenge dressing removal, the degree of erythema and oedema was quantified, and any other reactions recorded. The percentage of test animals that showed a more severe reaction at the test substance challenge site than the most severe reaction observed in the control animals, was compared using the scale: 0% = non-sensitiser; >0-8% = weak sensitiser; >8-28 = mild sensitiser; >28-64% = moderate sensitiser; >64-80% = strong sensitiser; >80-100% = extreme sensitiser.
Challenge controls:
Negative controls only.
Positive control substance(s):
no

Study design: in vivo (LLNA)

Statistics:
Not required.

Results and discussion

Positive control results:
No positive control.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
75 and 100%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
None
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 75 and 100%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: None.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
75 and 100%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
None
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 75 and 100%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: None.

Any other information on results incl. tables

Body weights of the guinea pigs in the test group between Day 0 and 24, were comparable to those observed in the control groups over the same period.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
In a GLP, skin sensitisation study (reliability score 1) conducted to OECD 406 (maximisation test), ammonium salt of ATMP was not sensitising to the skin of guinea pigs. The result is a read across from the ammonium salt (CAS 34274-28-7).
Executive summary:

In a GLP, skin sensitisation study (reliability score 1) conducted to OECD 406 (maximisation test), ammonium salt of ATMP was not sensitising to the skin of guinea pigs.