3-(triethoxysilyl)propyl methacrylate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

An LLNA study was not performed because there is an existing reliable study for skin sensitisation using the Guinea Pig Maximisation test method. Furthermore, the study pre-dates REACH Regulation (EC No 1907/2006) and CLP Regulation (EC No 1272/2008) requirements, which took place in 2007. According to the requirements the first choice in vivo test method for skin sensitisation is the murine local lymph node assay (LLNA).

Test material

Test material information

Constituent 1

Reference substance name:

(trimethoxysilyl)methyl methacrylate

EC Number:

611-170-6

Cas Number:

54586-78-6

IUPAC Name:

(trimethoxysilyl)methyl methacrylate

Test material form:

liquid

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, D33178 Borchen
- Weight at study initiation: 300-500g
- Housing: the animals were kept in groups in Terluran cages on Altromin saw fibre bedding, max group size 10 animals
- Diet: Altromin 3122 maintenance diet for guinea pigs, rich in crude fibre, ad libitum
- Water: tap water, ad libitum
- Acclimation period: described as 'adequate'

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/-3
- Humidity (%): 55 +/-10%
- Air changes (per hr): minimum of 10
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal

Vehicle:

corn oil

Concentration / amount:

For the intradermal injection (induction - first stage) the test item was applied at a 2.5% concentration (diluted in corn oil). For the topical application (induction - second stage) the test item was applied at a 100% concentration. For the topical application (challenge) the test item was applied at 100% concentration.

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

For the intradermal injection (induction - first stage) the test item was applied at a 2.5% concentration (diluted in corn oil). For the topical application (induction - second stage) the test item was applied at a 100% concentration. For the topical application (challenge) the test item was applied at 100% concentration.

No. of animals per dose:

10/5 (test/control)

Details on study design:

RANGE FINDING TESTS: For the justification of dose levels a preliminary test was performed. Three animals were intradermally treated with 1%, 2.5% and 5% concentration of the test item. For the 1% concentration slight signs of erythema (grade 1) were recorded 24h as well as 48h after application. These symptoms had disappeared 72 h after application. For the 5% concentration erythema grade 1, as well as necrotic formations, was recorded at the 24h, 48h as well as 72 hours reading. For the 2.5% concentration erythema grade 1 was recorded 24h, 48h as well as 72 hours after application.

Therefore, the concentration of 2.5% was chosen for the intradermal induction. Two animals were topically treated with 50% as well as 100% for 24 h and 48 hours respectively. No signs of irritation and systemic toxicity were recorded during the observation time for the animals. Therefore the 100% concentration was chosen for the topical induction as well as for the challenge.

MAIN STUDY
A. INDUCTION EXPOSURE

FIRST STAGE: INTRADERMAL INJECTION

Three pairs of intradermal injections of 0.1ml volume were given in the shoulder region which was cleared of hair by clipping so that one of each pair lies on each side of the midline.

Test group: Day 0
Injection 1: Freund's Adjuvant complete, 1 + 1 (v/v) diluted with isotonic saline
Injection 2: Prepared test item
Injection 3: Prepared test item at a concentration of 50% (v/v) in Freund's Adjuvant complete, 1+1 (v/v) diluted with isotonic saline

Control group: Day 0
Injection 1: Freund's Adjuvant complete, 1+1 (v/v) diluted with isotonic saline
Injection 2: vehicle
Injection 3: vehicle at a concentration of 50% (v/v) in Freund's Adjuvant complete, 1+1 (v/v) diluted with isotonic saline

Injections 1 and 2 were given close to each other and nearest to the head, while 3 is given toward the caudal part of the test area.

SECOND STAGE: TOPICAL APPLICATION

Test and control group: Day 6
Approximately 24 hrs before the topical induction application the test area, after close clipping, was painted with 0.5ml of 10% sodium lauryl sulphate in vaseline, in order to create a local irritation.

Test group: Day 7
A patch was loaded with 0.5ml of the prepared test item, applied to the test area and held in contact by an occlusive dressing for 48 hours.

Control group: Day 7
A patch was loaded with 0.5ml of the vehicle and applied to the test area and held in contact by an occlusive dressing for 48 hours.



B. CHALLENGE EXPOSURE

TOPICAL APPLICATION

The flanks of treated and control animals were cleared of hair by closely clipping and the use of depilation creme.

Test and control group: Day 20

A patch loaded with 0.5ml of the prepared test item was applied to the left flank of the animals and a patch loaded with 0.5ml vehicle to the right flank (intraspecific control), respectively. The patches were held in contact by an occlusive dressing 24 hours.


OBSERVATION

Test and control group

Approximately 21 hours after removing the patch the challenge area was cleaned and cleared of hair. Approximately 24 hours after removing of the patch the skin reaction was observed and recorded according to the grades shown below. Two more observations were recorded 48 and 72 hours after patch removal. Additionally, all animals have been observed for signs of toxicity at least once daily during the test period.

Positive control substance(s):

yes

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 3

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

no indication of skin sensitisation

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

no indication of skin sensitisation

Results 5

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

15% Mercaptobenzothiazole

Remarks on result:

other: sensitization rate of 70%

Any other information on results incl. tables

In all animals slight signs of erythema were recorded 24 h as well as 48 hours after first application. No other signs of irritation were observed in any of the animals neither after the intradermal application (induction first stage). No signs of irritation were observed after the topical application (induction second stage).

Challenge readings: The results of the test animals at the challenge phase were compared with the results of the control animals. No signs of irritation were observed after the challenge. The maximum percentage of animals sensitized was 0%. Animals of both groups survived throughout the test period. Animals of the test group showed neither reduced weight gain as compared to historical data and the animals of the control group, nor any other signs of toxicity.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test material was found not sensitising in a guideline study which was compliant with GLP.

Executive summary:

Slight signs of erythema were recorded in all animals 24 h and 48 hours after the first application. No other signs of irritation were observed in any other animal neither after the intradermal application (induction first stage), nor after the topical application (induction second stage).

Challenge readings: The results of the test animals at the challenge phase were compared with the results of the control animals. No signs of irritation were observed after the challenge. The maximum percentage of animals sensitized was 0%. Animals of both groups survived throughout the test period. Animals of the test group showed neither reduced weight gain as compared to historical data and the animals of the control group, nor any other signs of toxicity.