Reaction mass of 1,2,2,6,6-pentamethylpiperidin-4-yl hexadecanoate and 1,2,2,6,6-pentamethylpiperidin-4-yl octadecanoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31 May - 12 June 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Experimental study conducted in GLP compliant lab according to EC and OECD test methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 1,2,2,6,6-pentamethylpiperidin-4-yl hexadecanoate and 1,2,2,6,6-pentamethylpiperidin-4-yl octadecanoate

EC Number:

700-792-4

Molecular formula:

C26H51NO2, C28H55NO2

IUPAC Name:

Reaction mass of 1,2,2,6,6-pentamethylpiperidin-4-yl hexadecanoate and 1,2,2,6,6-pentamethylpiperidin-4-yl octadecanoate

Test material form:

other: white to pale yellow solid

Details on test material:

- Name of test material (as cited in study report): T-1640L
- Physical state: white to pale yellow solid
- Analytical purity: 98.74%
- Purity test date: 20 May 2011
- Lot/batch No.: 10121
- Expiration date of the lot/batch: 12 April 2013
- Stability under test conditions: stable
- Storage condition of test material: refrigerated in the dark under dry conditions

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: accredited commercial supplier
- Age at study initiation: 8-12 weeks at start of dosing
- Weight at study initiation: 17.6 - 20.8g
- Housing: solid bottomed polycarbonate cages with a stainless steel mesh lid.
- Diet (e.g. ad libitum): ad libitum, (Rat and Mouse No. 1 Maintenance Diet
- Water (e.g. ad libitum): ad libitum, potable water from domestic supply
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23C
- Humidity (%): 40-70%
- Air changes (per hr): The animal room was kept at positive pressure with respect to the outside by its own supply of filtered fresh air, which was passed to atmosphere and not re-circulated.
- Photoperiod (hrs dark / hrs light):12 hrs light/ 12 hrs dark

IN-LIFE DATES: From: To: 31 May - 12 June 2012

Study design: in vivo (non-LLNA)

Induction

Vehicle:

other:

Challenge

Vehicle:

other:

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

0, 10%, 25%, 50%, w/v

No. of animals per dose:

4

Details on study design:

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method:
- Criteria used to consider a positive response: Results for each treatment group were expressed as the Stimulation Index (SI). This was derived by dividing the mean dpm/mouse for each treated group and the positive control group by the mean dpm/mouse in the vehicle control group.
If the SI is 3 or more, the test substance is regarded as a skin sensitizer.
The positive control group is expected to give an SI of 3 or more to demonstrate the validity of the study.

TREATMENT PREPARATION AND ADMINISTRATION:
The mice were treated by daily application of 25 µL of the appropriate concentration of the test substance to the dorsal surface of each ear for three consecutive days (Days 1-3). The test substance was applied to the dorsal surface of each ear using an automatic micropipette and was spread over the entire dorsal surface of the ear using the tip of the pipette. Further groups of four mice received the vehicle alone or the positive control substance in the same manner.

Five days following the first topical application of test substance (Day 6) all mice were injected via the tail vein with 250 µL of phosphate buffered saline containing 3H-methyl Thymidine (3HTdR: 80 µCi/mL) giving a nominal 20 µCi to each mouse. The injection into the tail vein was carried out using a plastic syringe and needle after the mouse had been heated in a warming chamber.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

Stimulation Index for positive control, hexyl cinnamic aldehyde, was 7.9 demonstrating that the study was valid.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: SI for each group was as follows: Dose SI 0 n/a 10% w/v 7.5 25% w/v 14.6 50% w/v 14.7

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Dose dpm/node 0 585.58 10% w/v 4386.47 25% w/v 8542.11 50% w/v 8583.62

Any other information on results incl. tables

There were no deaths and no signs of ill health or toxicity were observed during this study.

Greasy fur on the head was noted in all animals following each dosing occasion, this was related to unoccluded dermal administration of a liquid formulation/vehicle and not an effect of the test substance. White dose residue was seen in two animals (D11, D12) from Day 2 and one animal (D10) from Day 3 dosed at 25% w/v. In addition white dose residue was also seen in all mice dosed at 50% w/v from Day 2. All signs had resolved by Day 5.

No signs of dermal irritation were seen on the ear during the study.

There was no indication of an effect of treatment on bodyweight gain.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

T-1640L is regarded as a potential skin sensitizer. The EC3 value was calculated to be 5.6% w/v.