N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-10-26 to 2010-01-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP-study according to OECD testing guide line.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate attached to full study report

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

EC Number:

700-253-3

Cas Number:

115258-10-1

Molecular formula:

C15H37NO4Si4

IUPAC Name:

N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/J@Rj

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Elevage Janvier (F-53941 Le Genest Saint Isle)
- Age at study initiation: 8 weeks
- Animals were nulliparous and non-pregnant
- Weight at study initiation: 20.3 - 24.5g
- Housing: suspended solid-floor polypropylene cages furnished with soft woodflakes
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25°C
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12hrs / 12hrs
- Animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

0% (vehicle control), 10%, 25%, 50% (as the test item was a powder, the maximum tested dose was 50%)

No. of animals per dose:

4 females

Details on study design:

PRELIMINARY STUDY
- Preliminary screening using one mouse
- The mouse was treated with 25µL of the undiluted test item
- Dorsal surface of each ear was treated on three consecutive days (d1, d2, d3)
- Daily observation of the treated animal on d1, d2, d3, d4, d5 and d6
- Any signs of toxicity or excessive local irritation noted during this period were recorded
- Body weight was recorded on day 1 prior to treatment and on day 6
- No systemic toxicity or excessive local reactions observed

MAIN STUDY
- Groups of four mice per each concentration
- Group 1: 4 females with vehicle only --> 0% of test item
- Group 2: 4 females with 10% test item
- Group 3: 4 females with 25% test item
- Group 4: 4 females with 50% test item
- An additional mouse was treated in each group in case of problems which may occur during the study, in particular during excision of lymph nodes
- Mice were treated by daily application of 25µL of the appropriate concentration of the test item to the dorsal surface of each ear for three consecutive days
- Test item formulation was administered using an automatic micropipette and spread over the dorsal surface using the tip of the pipette

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Ear thickness and cell proliferation
- See specific details under: "Any other information on materials and methods incl. tables"

CRITERIA USED TO CONSIDER A POSITIVE RESPONSE:
- The test item will be regarded as a sensitiser if at least one concentration of the test item results is greater than 1.4 compared to control values
- Any test item failing to produce a SI<1.4 will be classified as a "non sensitiser"
- % increase in ear thickness between day 1 and day 6

Positive control substance(s):

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

Results and discussion

Positive control results:

See attached tables (historical controls)

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: SI calculated by pooled approach was: 1.23 (10%), 1.03 (25%), 1.05 (50%) i.e. no stimulation index of more than 1.4 was recorded for either of the three concentrations

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Other method: cell counting and ear thickness

Any other information on results incl. tables

Preliminary screening test

Clinical observations, bodyweight and mortality data are given in Table 1 (attached).

No signs of systemic toxicity were noted.

Based on this information the dose levels selected for the main test were 10% (v/v), 25% (v/v) and50% (w/w) in acetone/olive oil (4:1, v/v).

Main Test

Clinical observations and mortality

Individual clinical observations and mortality data for test and control animals are given in Table 2 (attached).

No mortality and no signs of systemic toxicity were noted in the test and controls animals during thetest.

Weight evolution

Individual bodyweights and bodyweight changes for test and control animals are given in Table 3 (attached).

The body weight evolution revealed an absence of body weight gain in the animals treated at theconcentration of 10% and a slight decrease in the body weight of the animals treated at theconcentrations of 25% and 50% (-9.5% and -9.1% compared to day 1, respectively).

Estimation of the proliferative response of lymph node cells

The results of proliferation assay are given in Table 4 (given here and also attached).

Groups	Test item	Cell count / groups (x10^6cells / mL)	Stimulation Index S.I.	Result	EC1.4value
1	AOO (acetone/olive oil, 4:1, v/v)	22.36	n.a	n.a	n.a.
2	10%	27.43	1.23	Negative	n.a.
3	25%	22.96	1.03	Negative
4	50%	23.38	1.05	Negative

Stimulation Index = Cell count of treated group / Cell count of control group

EC1.4 value: Theorical concentration resulting in a SI value of 1.4

EC1.4=c + [(1.4 – d) / (b – d)] x (a – c)

Legend:                                                                                               

a = the lowest concentration giving stimulation index > 1.4

b = the actual stimulation index caused by a

c = the highest concentration failing to produce a stimulation index of 1.4

d = the actual stimulation index caused by c

 No stimulation index of more than 1.4 was recorded for the three concentrations of the test item.

The Stimulation Index (SI) calculated by pooled approach was respectively 1.23, 1.03 and 1.05 for the treated group at 10%, 25% and 50%.

Local irritation

The results of ear thickness measurement and weight of skin biopsy are given in Tables 5 and 6 (both attached).

No cutaneous reactions were observed at the concentrations of 10%, 25% and 50%.

No significant increase in ear thickness and in ear weight was recorded at the concentrations of 10%, 25% and 50%. Therefore, the test item must be considered “non irritant” at the three concentrations.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In view of these results, under these experimental conditions, the test item N-[3- tris(trimethylsilyloxy)silylpropyl]prop-2-enamide is considered to be not a skin sensitiser, in accordance with the criteria for classification, packaging and labelling of dangerous substances and preparations of the E.E.C. Directives 67/548, 2001/59 and 99/45. No symbol and risk phrase are required.
In accordance with the Globally Harmonized System (Regulation (EC) No. 1272/2008), the test item is not to be classified. No signal word and hazard statement are required.

Executive summary:

The test was performed to assess the skin sensitisation potential of the test item N-[3-tris(trimethylsilyloxy)silyl)silylpropyl]prop-2 -enamide in the CBA/J strain mouse following topicalapplications to the dorsal surface of the ear.

Three groups of four animals, were treated for three consecutive days (D1, D2, D3) with 50 µL (25 µLper ear) of the test item as a solution in acetone/olive oil (4:1, v/v) (AOO) at concentrations of 10%,25% and 50% (v/v). A further group of four animals was treated with AOO.

On D6, the proliferation of lymphocytes in the draining auricular lymph nodes was determined by cell counting. The experimental protocol was established according the OECD Guideline n°429 dated April 24^th, 2002 and the test method B.42 of the council regulation No.440/2008.

No mortality and no signs of systemic toxicity were noted in the test and control animals during the test.

The body weight evolution revealed an absence of body weight gain in the animals treated at the concentration of 10% and a slight decrease in the body weight of the animals treated at the concentrations of 25% and 50% (-9.5% and -9.1% compared to day 1, respectively).

No cutaneous reaction was observed.

No significant increase in ear thickness and in ear weight was recorded at the concentrations of 10%, 25% and 50%. Therefore, the test item must be considered “non irritant” at the three concentrations.

The Stimulation Index (SI) calculated by pooled approach was1.23, 1.03 and 1.05 for the treated groups at 10%, 25% and 50%, respectively.

In view of these results, under these experimental conditions, the test item N-[3 -tris(trimethylsilyloxy)silyl)silylpropyl]prop-2 -enamide is considered to be not a skin sensitiser, in accordance with the criteria for classification, packaging and labelling of dangerous substances and preparations of the E.E.C. Directives 67/548, 2001/59 and 99/45. No symbol and risk phrase are required.

In accordance with the Globally Harmonized System (Regulation (EC) No 1272/2008), the test item is not to be classified. No signal word and hazard statement are required.