2-butanone-O,O',O''-(phenylsilylidyne)trioxime

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-05-12 to 1999-06-07

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test method according to EEC, OECD and EPA test guidelines, with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

433-360-6

EC Name:

-

Cas Number:

34036-80-1

Molecular formula:

C18H29N3O3Si

IUPAC Name:

6-{[(butan-2-ylidene)amino]oxy}-3,9-dimethyl-6-phenyl-5,7-dioxa-4,8-diaza-6-silaundeca-3,8-diene

Constituent 2

Reference substance name:

2-butanone-O,O',O''- (phenylsilylidyne)trioxime

IUPAC Name:

2-butanone-O,O',O''- (phenylsilylidyne)trioxime

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): OS-9000
- Physical state: Clear liquid
- Analytical purity: >92%
- Lot/batch No.: M-350B
- Expiration date of the lot/batch: 12 February 2000

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: D. Hall, Newchurch, Staffs, UK
- Age at study initiation: Four to seven weeks of age
- Weight at study initiation: 383 - 447 g
- Housing: In groups of five in suspended metal cages with wire mesh floors.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS:
-Temperature: 18 to 26.5ºC
- Humidity: 37 to 64%.
- Photoperiod: 12 hours of artificial light (0700 - 1900 hours GMT).

IN-LIFE DATES: from: May 12 to June 7 1999

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: (acetone in Alebicol D for intradermal injections, and acetone for topical application)

Induction 2

Concentration / amount:

Induction intradermal injection - 1% v/v in 5% acetone in Alembicol D
Induction topical application - as supplied
Topical challenge - 50 and 25% v/v in acetone

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: (acetone in Alebicol D for intradermal injections, and acetone for topical application)

Challenge 2

Concentration / amount:

Induction intradermal injection - 1% v/v in 5% acetone in Alembicol D
Induction topical application - as supplied
Topical challenge - 50 and 25% v/v in acetone

No. of animals per dose:

10 females in the test group.
5 females in the control group.

Details on study design:

RANGE FINDING TESTS:
The intradermal and topical irritancy of a range of dilutions of the test substance was investigated to determine concentrations that would produce irritation suitable for the induction phase of the main study and the maximum non-irritant concentration by the topical route of administration for the challenge phase. 1% v/v in 5% acetone in Alembic01 D was the highest concentration that caused initation but did not adversely affect the animals. The test substance applied topically as supplied produced some slight irritation but did not adversely affect the animals.

MAIN STUDY
A. INDUCTION EXPOSURE (intradermal and dermal)
- No. of exposures: 1 intradermal (three pairs of injections) and 1 dermal
- Exposure period: - (intradermal), 48 hours (dermal)
- Test groups: Test substance, Test substance + FCA, FCA
- Control group: FCA, FCA + vehicle, vehicle
- Site: A 40 x 60 rnm area of dorsal skin on the scapular region of the guinea-pig was clipped free of hair with electric clippers
- Frequency of applications: Intradermal on day 0, dermal at day 7
- Duration: 7 days
- Concentrations:
Intradermal induction (three pair of injections):
Test substance: 1% v/v in 5% acetone in Alembicol D
Test substance + FCA: 1% v/v in a 50:50 mixture of FCA and 5% acetone in Alembicol D
FCA: diluted with an equual volume of water
Topical induction:
Six days after the injectionshe site was pre-treated by gentle rubbing with 0.5 ml per site of 10% wlw sodium lauryl sulphate in petrolatum. 24 hours
later a 20 x 40 mm patch of paper was saturated with approximately 0.4 test substance as supplied. The patch was placed on the skin of the test animals and covered by a length of impermeable plastic adhesive tape. This was firmly secured by elastic adhesive bandage wound round the torso of the animal and fixed with impervious plastic adhesive tape. The dressing was left in place for 48 hours.

B. CHALLENGE EXPOSURE
- No. of exposures: 1 for each concentration of challenge)
- Day(s) of challenge: 21 (two weeks after induction)
- Exposure period: 24 hours
- Test groups: Test substance
- Control group: Test substance
- Site: Hair was removed by clipping and then shaving from an area on the left flank of each guinea-pig. A 20 x 20 mm patch of paper was saturated with approximately 0.2 ml of test substance 50% v/v in acetone and applied to an anterior site on the flank. 25% v/v of test item in acetone was applied in a similar manner to the posterior site. The patches were sealed to the flank for 24 hours under strips covered by wound round the trunk and secured.
- Concentrations: 50 and 25 % in acetone (see comment below)
- Evaluation (hr after challenge): 24, 48, 72 hours.

OBSERVATIONS:
Clinical signs: All animals were observed daily for signs of ill health or toxicity.
Bodyweight: The bodyweight of each guinea-pig on the main study was recorded on Day 1 (day of intradermal injections) and on the last day observations were made of dermal responses to the challenge application.
Dermal responses: The dermal reactions resulting from intrademl injection and topical application on the preliminary study, and topical application at the challenge were assessed using Draize scoring system.


FCA = Freund's Complete Adjuvant

Challenge controls:

The control were also challenged topically two weeks after the topical induction application using 50 and 25% v/v of tes item in acetone.

Positive control substance(s):

yes

Remarks:

(priodically checked by the laboratory)

Results and discussion

Positive control results:

The positive controls are periodically checked by Huntingdon Life Sciences to detect skin sensitization potential. The last study was performed between 22 December 1998 and 15 January 1999. In this study HCA produced evidence of skin sensitisation (delayed contact hypersensitivity) in all of the ten animals, thus confirming the sensitivity and reliability of the experimental technique.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

1 % intradermal induction

No. with + reactions:

4

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 1 % intradermal induction. No with. + reactions: 4.0. Total no. in groups: 10.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1 % intradermal induction

No. with + reactions:

6

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1 % intradermal induction. No with. + reactions: 6.0. Total no. in groups: 10.0.

Results 3

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

1 % intradermal induction

No. with + reactions:

6

Total no. in group:

10

Remarks on result:

other: Reading: other: 3rd reading. . Hours after challenge: 72.0. Group: test group. Dose level: 1 % intradermal induction. No with. + reactions: 6.0. Total no. in groups: 10.0.

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

1 % intradermal induction

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 1 % intradermal induction. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 5

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

1 % intradermal induction

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 1 % intradermal induction. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 6

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

negative control

Dose level:

1 % intradermal induction

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: other: 3rd reading. . Hours after challenge: 72.0. Group: negative control. Dose level: 1 % intradermal induction. No with. + reactions: 0.0. Total no. in groups: 5.0.

Any other information on results incl. tables

Clinical signs:

No signs of ill health or toxicity were observed.

Body weight:

Bodyweight increases were recorded for all guinea-pigs over the period of the study.

Induction:

Intradermal injections: Necrosis was recorded at sites receiving FCA in test and control animals. Slight imtation was seen in test animals at sites receiving test item, 1% v/v in 5% acetone in Alembicol D and slight imtation was observed in control animals receiving 5% acetone in Alembicol D.

Topical application: No erythema was observed in test animals following topical application with test item, as supplied. No erythema was seen in the control guinea-pigs.

Challenge:

Dermal reactions were noted in six of the ten test animals compared to none in controls, therefore these six test animals gave positive responses. No reactions were noted for the remaining four animals therefore they gave negative responses.

Dermal reactions observed after the challenge application with test item:

Test substance group:

Animal	E=Erythema O=Oedema	Score						Result
		24 h		48 h		72 h
		A	P	A	P	A	P
1	E O	0 0	0 0	0 0	0 0	0 0*	0 0	-
2	E O	1 1	0 0	1 1*	0 0	2 1*	0 0	+
3	E O	0 0	0 0	1* 0	0 0	1 0*	0 0	+
4	E O	2 1	0 0	2 1*	0 0	2 1*	0 0	+
5	E O	0 0	0 0	1 0*	0 0	1 0*	0 0	+
6	E O	1 1	0 0	1 1*	0 0	1 1*	0 0	+
7	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
8	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
9	E O	1 1	0 0	1 0*	0 0	1 0*	0 0*	+
10	E O	0 0	0 0	0 0	0 0	0 0	0 0	-

* Dryness and sloughmg of the epidermis

A Anterior site, exposed to 0s-9000, 50% v/v in acetone

P Posterior site, exposed to 0s-9000,25% vlv in acetone

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item produced evidence of skin sensitization (delayed contact hypersensitivity) in six of the ten test animals, and therefore the substance isconsidered to have the potential to cause skin sensitization.

Executive summary:

A guinea pig maximization test was performed to assess the skin sensitization potential of test item using the guinea pig. The method followed was according to EEC method B.6, OECD guideline 406 and EPA OPPS 870.2600. The guinea pigs were dosed by intradennal injection and topical application. Based on the results of a preliminary study and in compliance with the guidelines, the guinea pigs were exposured to intradermal injections of 1% v/v in 5% acetone in Alembicol D, a topical application of the substance as supplied and a challenge application of 50 and 25% vlv in acetone. Ten test and five control guinea pigs were used. In this study, the test substance produced evidence of skin sensitization (delayed contact hypersensitivity) in six of the ten test animals, and therefore, it was considered to have the potential to cause skin sensitization.