2,2,6,6-Tetramethylpiperidin-4-yl dodecanoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and OECD guideline compliant study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

(FREY-TOX GmbH, Herzberg / Elster, Germany)

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

2,2,6,6-tetramethylpiperidin-4-yl dodecanoate

EC Number:

700-503-1

Cas Number:

101238-01-1

Molecular formula:

C21 H41 N O2

IUPAC Name:

2,2,6,6-tetramethylpiperidin-4-yl dodecanoate

Details on test material:

- Analytical purity: 94%

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: SPF albino guinea pigs of the stock Crl:HA

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH, Sulzfeld, Germany
- Weight at study initiation: 287 - 365 g
- Housing: two or three animals in each macrolone cage
- Diet: Altromin 3123 (Altromin, Lage, Lippe, Germany); ad libitum
- Water: vitamin C enriched domestic quality water that was acidified to pH 2.5 with hydrochloric acid; ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C +/- 3°C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 h / 12 h

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

polyethylene glycol

Remarks:

(PEG E400)

Induction 2

Concentration / amount:

1st induction: 2.5%, 2nd induction: 1%, 3rd induction: 1%, challenge: 0.5%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

polyethylene glycol

Remarks:

(PEG E400)

Challenge 2

Concentration / amount:

1st induction: 2.5%, 2nd induction: 1%, 3rd induction: 1%, challenge: 0.5%

No. of animals per dose:

control group: 10; test group: 20

Details on study design:

RANGE FINDING TESTS:
During a first preliminary investigation, two female animals were initially treated with four concentrations of the test item of 25%, 50%, 75% and 100%. The response of the guinea pigs to this treatment was unexpectedly intense indicating a moderate to severe reduction of the general state of health and severe skin reactions. Immediately after termination of 6-hour exposure, an intense heat and redness of skin was observed on the treated body areas. Posture, mimic, vocal utterance and behaviour of the animals as well as occurence of tremor and hypothermia revealed distinct signs of pain of the animals. After cleaning and drying of the treated skin areas, the animals were wrapped in warm towels and their cage was temorarily put into a very warm environment. Under these conditions, the general state of health of the animals improved and only a slight impairment was still discernible after 6 hours. After that, a modified procedure concerning further preliminary investigations and a reduction of the test concentration were decided. During a second and third preliminary investigation, only one concentration of the test item (5% or 10% (w/w)) was tested in two female animals each. These animals still showed disrete to intense erythema, but no comparable systemic reactions. Therefore, a fourth preliminary investigation was performed with the 1% and 2.5% (w/w) test item and two male animals. Based on the results, a concentration of 2.5% was initially selected for the induction and a concentration of 1% for the challenge application. However and due to the moderate skin reactions in the test group during the induction phase, it was decided to perform the 2nd and 3rd induction only with 1% (w/w) test item and the challenge treatement with 0.5% (w/w).

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 3 x 6 h
- Test groups: day 0: A patch of multilayered gauze (2.5 x 2.5 cm) coated occlusively with impermeable tape (Blenderm) on one side was saturated with 0.5 mL of 2.5% (w/w) test item and the patch was placed on the skin of all test group animals. The fixation of this occlusive dressing was made by wrapping the trunk of the animals with Gothaplast tape. The dressings were removed after 6 h and residues of the test item were washed off from the skin initially with a watery 50% solution of PEG E 400 and subsequently with pure water. The procedure was repeated on days 7 and 14, but with a lower concetration (1%). The test sites were assessed for skin irritation 24 h after each patch application.
- Control group: treated like test groups, but with the vehicle PEG E 400 only
- Site: left flank region
- Frequency of applications: 3 applications (day 0, day 7, day 14)
- Duration: 6 h
- Concentrations: 1st induction: 2.5%, 2nd induction: 1%, 3rd induction: 1%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: day 28 (4 weeks after the 1st induction)
- Exposure period: 6 h
- Test groups: A patch of multilayered gauze (2.5 x 2.5 cm) coated occlusively with impermeable tape (Blenderm) on one side was saturated with 0.5 mL of 0.5% (w/w) test item and the patch was placed on the skin of the anterior part of the right flank. In the same way an occlusively coated patch of multilayered gauze (2.5 x 2.5 cm) was saturated with 0.5 mL of the vehicle PEG E 400 and placed psterior on the right flank. The fixation of this occlusive dressing was made by wrapping the trunk of the animals with Gothaplast tape. The dressings were removed after 6 h and residues of the test item were washed off from the skin initially with a watery 50% solution of PEG E 400 and subsequently with pure water.
- Control group: treated like test groups, but with the vehicle PEG E 400 only
- Site: right flank region
- Concentrations: 0.5%
- Evaluation (hr after challenge): 24 and 48 h after the removal of the patch (about 6 h before the 24 h reading, the sites were clipped and shaved in order to facilitate the evaluation)

OTHER: The animals were observed at least once a day for signs of illness and reactions to the treatment. The animals of the main study were weighed at the beginning of the study (day 0) and at the end of the study (day 33).

Positive control substance(s):

yes

Remarks:

(The last positive control test with the reference material alpha-Hexylcinnamaldehyde (tech., 85%) was performed from March 2013 until May 2013. 85% of the guinea pigs showed a positive response ( erythema grade 1 and 2).)

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No visible change.

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No visible change..

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No visible change.

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No visible change..

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.5%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No visible change.

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No visible change..

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.5%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No visible change.

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No visible change..

Any other information on results incl. tables

No signs of illness were observed in the animals of the main study. They had a normal body weight gain during the study period.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU