N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)isophthalamide

Skin sensitisation

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 guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

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

Test material information

Constituent 1

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)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: absolute ethanol

Concentration / amount:

Induction:
- intradermal: 10% (w/w)
- topical: 60% (w/w)

Challenge:
- topical: 60% (w/w)

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: absolute ethanol

Challenge 2

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)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0

No. with + reactions:

0

Total no. in group:

0

Remarks on result:

not measured/tested

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

0

No. with + reactions:

0

Total no. in group:

0

Remarks on result:

not measured/tested

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

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.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

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.

Results 5

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.

Results 6

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.