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Toxicological information

Skin sensitisation

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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:
1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline conform GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Study on skin sensitization already performed under Directive 67/548/EC, before REACH entered into force.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River France (Cleon, France)
- Age at study initiation: 6 weeks
- Weight at study initiation: 250 - 550 g
- Housing: in groups according to EEC/86/609 in stainless stell mesh cages
- Diet (e.g. ad libitum): pelleted complete guinea pig diet, ad libitum
- Water (e.g. ad libitum): softened and filtered mains drinking water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19+/-3°C
- Humidity (%): >/= 45%
- Air changes (per hr): >/= 22
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: absolute ethanol
Concentration / amount:
Induction:
- intradermal: 10% (w/w)
- topical: 60% (w/w)

Challenge:
- topical: 60% (w/w)
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: absolute ethanol
Concentration / amount:
Induction:
- intradermal: 10% (w/w)
- topical: 60% (w/w)

Challenge:
- topical: 60% (w/w)
No. of animals per dose:
Number of animals in test group: 20
Number of animals in negative control group: 10
Details on study design:
Control: 5 males, 5 females
Treatment group: 10 males, 10 females


- Intradermal induction
Administration area: 2x4 cm on the clipped dorsal shoulder region
Time of injection: day 1
Three pairs of intradermal injections were performed to the retroscapsular region left and right of the spine, in an approx. 2x4 cm area

1. Freund's complete adjuvant at 50% (v/v) in an isotonic injectable aolution
2. test article in a 10% (w/w) solution in absolute ethanol
3. mixture 50/50 (v/v): test article in a 20% (w/w) suspensin in absolute ehtanol + Freuns's complete adjuvant at 50% (v/v) in an isotonic injectable solution, i.e. a final 10% concentration of the test item.
Injection of the test item in a 10% solution provoked a moderate irritation with burnt appearance to the injection sites during the preliminary study.

- Topical application (48 h exposure)
Application area: clipped and shaved area, corresponding to that used for intradermal injections
Time of administration: day 9
0.5 mL test item in a 60% (w/w) paste in absolute ethanol
The test item was applied under an occlusive dressing composed of filter paper 2x4 cm maintained in contact with the skin with a waterproof and hypo-allergenic tape.Fixing of this tape was reinforced with a 4 cm wide linen adhesive tape applied on a hydrophilic gauze pad covering the whole clipped surface to avoid possible irritation by the adhesive tape.
As this application only provoked a weak irritation during the preliminary study, a skin painting was performed during the main study on day 8, with 0.5 mL of sodium lauryl sulphate at 10% (w/w) in Codex paraffin to create irritation.

- Control group
The intradermal injections and the topical occlusive application for 48 h were carried out under the same conditions as in the treated group, absolute ethanol replacing the test item.

- Rest period: day 11 to 22
Challenge controls:
- Challenge application
day 22
Application area: a 2x2 cm area on the left flank of each animal, close-clipped and shaved
The topical occlusive application for 24 h was performed in the treated group and the control group with the test item in a 60% (w/w) paste in absolute ethanol and at the dose level of 0.5 mL. The vehicle was also applied during challenge.
The cutaneous macroscoppic examinations were performed 24 and 48 h after removel of the occlusive dressing to the challenge applications sites, according to the Magnusson & Kligman scale.
Histopathological examination of the skin was performed for one animal of the treated group which showed doubtful macroscopic reaction at 24 h.
Positive control substance(s):
yes
Remarks:
DCNB (1-Chlor-2,4-Dinitrobenzol)

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
60 %
No. with + reactions:
1
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 60 %. No with. + reactions: 1.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
60 %
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 60 %. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
60 %
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 60 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
60 %
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 60 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
From the results obtained under the experimental conditions employed the test item is regared as not sensitising.
Executive summary:

Testing for sensitising properties of N,N’-Bis(2,2,6,6-tetramethyl-4-piperidinyl)isophthalamide was performed in male and female guinea pigs according to the Magnusson & Kligman test (PPMT). Intradermal induction was performed using 10 % N,N’-Bis(2,2,6,6-tetramethyl-4-piperidinyl)isophthalamide, topical induction with 60% substance in paste. The challenge was carried out with 60% N,N’-Bis(2,2,6,6-tetramethyl-4-piperidinyl)isophthalamide (epidermal) 12 days after the last induction application.

The test item induced allergic reactions in only one out of twenty animals.

N,N’-Bis(2,2,6,6-tetramethyl-4-piperidinyl)isophthalamide is regarded as not sensitising.