Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

9th September 1985 to 7th October 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study is conducted by recognised test house, to experimental procedures in compliance with OECD Guideline 406. Full data set and rationale provided. GLP compliance not specified, although report is subject to Quality Assurance Procedure.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

not specified

Remarks:

No mention of GLP is made within the report; however the report was subject to Quality Assurance at the laboratory where the testing was conducted. As such, it is assumed that the principles of GLP were followed.

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

EC Number:

403-360-0

EC Name:

Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

Cas Number:

42405-40-3

Molecular formula:

C30H42O6Zn

IUPAC Name:

bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

Details on test material:

- Name of test material (as cited in study report): Bontron E-84
- Substance type: Solid
- Physical state: White Powder
- Analytical purity: Not specified
- Lot/batch No.: No batch number is specified within the report, but the test substance is deemed equivalent based on history of manufacture and use.
- Stability under test conditions: Not determined
- Storage condition of test material: Ambient temperatures

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, Staffordshire, England
- Age at study initiation: Not specified
- Weight at study initiation: 382 to 482 g
- Housing: Housed in suspended cages with wire mesh floors
- Diet (e.g. ad libitum): Vitamin C enriched Guinea Pig diet F.D.1 (Special Diet Services Limited) ad libitum. Hay was provided once weekly.
- Water (e.g. ad libitum): Tap water, ad libitum
- Acclimation period: Timescale not specified, although report states that the guinea pigs selected for the study were all acclimated to the laboratory environment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Approximately 21°C
- Humidity (%):30 - 70 %
- Air changes (per hr): Approximately 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours of artificial light in each 24 hour period.

IN-LIFE DATES: From: 9th September 1985 To: 7th October 1985

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: Acetone / Alembicol D

Induction 2

Concentration / amount:

The following concentrations were selected:

Induction:
Intradermal injection: 0.25% substance w/w in acetone, 5% v/v in Alembicol D
Topical application: 50% substance w/w in acetone

Challenge:
50% (anterior site) and 20% (posterior site) substance w/w in acetone.

Challenge

Challenge 1

Route:

epicutaneous, semiocclusive

Vehicle:

other: Acetone / Alembicol D

Challenge 2

Concentration / amount:

The following concentrations were selected:

Induction:
Intradermal injection: 0.25% substance w/w in acetone, 5% v/v in Alembicol D
Topical application: 50% substance w/w in acetone

Challenge:
50% (anterior site) and 20% (posterior site) substance w/w in acetone.

No. of animals per dose:

20 test + 10 Control

Details on study design:

RANGE FINDING TESTS:
The intradermal irritancy of a range of dilutions of the test substance in acetone, 5% v/v in Alembicol D and the topical irritancy of the substance in acetone were investigated to identify:
a) irritant test substance concentrations where possible, suitable for the induction phase of the main study
b) non-irritant concentrations by the topical route of administration for the challenge phase.

MAIN STUDY
A. INDUCTION EXPOSURE
Induction:
A 4 x 6 cm area of dorsal skin on the scapular region of the guinea pig was clipped free of hair with electric clippers. Three pairs of intradermal injections were made simultaneously into this area (please see attached table for location details). Injectables were prepared as follows:
1. Freunds Complete Adjuvant (FCA) diluted with an equal volume of water for irrigation.
2. Test substance, 0.25% w/w in acetone, 5% v/v in Alembicol D
3. Test substance, 0.25% w/w in a 50:50 mixture of FCA/Acetone, 5% v/v in Alembicol D

Topical Application:
One week after the injections, the same 4x6 cm interscapular area was clipped and shaved free of hair. A 2x4 cm patch of Whatman No.3 paper was saturated with the test substance 50% w/w in acetone. The patch was placed on the skin and covered by a length of impermeable plastic adhesive tape (5cm width "Blenderm"). This in turn was firmly secured by elastic adhesive bandage ("Elastoplast", 5cm width) wound around the torso of the animal and fixed with "Sleek" impervious plastic adhesive tape. The dressing was left in place for 48 hours.


B. CHALLENGE EXPOSURE
The test and control animals were challenged topically two weeks after the induction period using the test substance at 50% and 20% wlw in acetone respectively.
Hair was removed by clipping and then shaving from an area on the left flank of each guinea pig. A 2x2 cm patch of Whatman No.3 paper was saturated with approximately 0.2 ml of the test substance, 50% w/w in acetone and applied to an anterior site on the flank. A 20% w/w in acetone preparation of the test substance was applied to a posterior site. The patches were sealed to the flank for 24 hours under strips of "Blenderm" covered by "Elasttoplast" wound round the trunk and secured with "Sleek".

Reading Challenge Reactions:
The challenge sites were evaluated 24, 48 and 72 hours after removal of the patches. Reactions were scored accordingly to the following scale:

Erythema and eschar formation:
No erythema: 0
Very slight erythema (barely perceptable): 1
Well defined erythema: 2
Moderate to severe erythema: 3
Severe erythema (beet redness) to slight eschar formation (injuries in depth): 4

Oedema Formation:
No oedema: 0
Very slight oedema (barely perceptable): 1
Slight oedema (edges of area well defined by definite raising): 2
Moderate oedema (raised approximately 1mm): 3
Severe oedema (raised more than 1 mm and extending beyond the area of exposure): 4

Interpretation of Results:
Dermal reactions in the test animals elicited by the challenge application were compared with the findings simultaneously obtained in the control animals.
A test animal was considered to show positive evidence of delayed contact hypersensitivity if the observed dermal reaction at challenge was definitely more marked and/or persistent than the maximum reaction seen in animals of the control group.
If the dermal reaction seen in a test animal at challenge was slightly more marked and/or persistent than (but not clearly distinguishable from) the maximum reaction seen in control animals, the result for that test animal was classified as inconclusive.
A test animal was considered to show no evidence of delayed contact hypersensitivity if the dermal reaction resulting from the challenge application was the same as or less marked and/or persistent than the maximum reaction seen in animals of the control group.

Challenge controls:

During the induction period, the group of 10 control animals were treated similarly to the test animals with the exception that the test compound was omitted from the intradermal injections and topical application.

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50% / 20% w/w in acetone

No. with + reactions:

3

Total no. in group:

20

Clinical observations:

3 animals displayed erythema score of 1 on anterior site only. Some localised dermal reactions noted in 5 animals, restricted to small area of the challenge site, anterior only.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50% / 20% w/w in acetone. No with. + reactions: 3.0. Total no. in groups: 20.0. Clinical observations: 3 animals displayed erythema score of 1 on anterior site only. Some localised dermal reactions noted in 5 animals, restricted to small area of the challenge site, anterior only..

Results 2

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50% / 20% w/w in acetone

No. with + reactions:

2

Total no. in group:

20

Clinical observations:

1 animal displayed erythema score of 1 on anterior site only; 1 animal displated oedema score of 1, anterior site only. Some localised dermal reactions noted in 8 animals, restricted to small area of the challenge site, anterior only.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50% / 20% w/w in acetone. No with. + reactions: 2.0. Total no. in groups: 20.0. Clinical observations: 1 animal displayed erythema score of 1 on anterior site only; 1 animal displated oedema score of 1, anterior site only. Some localised dermal reactions noted in 8 animals, restricted to small area of the challenge site, anterior only..

Results 3

Reading:

1st reading

Hours after challenge:

72

Group:

test chemical

Dose level:

50%/20% w/w in acetone

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Some localised dermal reactions noted in 8 animals, restricted to small area of the challenge site, anterior only.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 72.0. Group: test group. Dose level: 50%/20% w/w in acetone. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Some localised dermal reactions noted in 8 animals, restricted to small area of the challenge site, anterior only..

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50%/20% w/w in acetone

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

2 animals displayed erythema score of 1,anterior only. Some localised dermal reactions noted in 3 animals, restricted to small area of the challenge site.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50%/20% w/w in acetone. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: 2 animals displayed erythema score of 1,anterior only. Some localised dermal reactions noted in 3 animals, restricted to small area of the challenge site..

Results 5

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

50%/20% w/w in acetone

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

2 animals displayed erythema score of 1, anterior only. Some localised dermal reactions noted in 4 animals, restricted to small area of the challenge site, anterior and posterior locations.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50%/20% w/w in acetone. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: 2 animals displayed erythema score of 1, anterior only. Some localised dermal reactions noted in 4 animals, restricted to small area of the challenge site, anterior and posterior locations..

Results 6

Reading:

1st reading

Hours after challenge:

72

Group:

negative control

Dose level:

50%/20% w/w in acetone

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

2 animals displayed erythema score of 1, anterior only. Some localised dermal reactions noted in 4 animals, restricted to small area of the challenge site, anterior and posterior locations.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 72.0. Group: negative control. Dose level: 50%/20% w/w in acetone. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: 2 animals displayed erythema score of 1, anterior only. Some localised dermal reactions noted in 4 animals, restricted to small area of the challenge site, anterior and posterior locations..

Any other information on results incl. tables

Dermal Reactions elicited by the challenge application – Test Animals.

Guinea Pig No	E=Erythema O=Oedema	Score						Results Positive (+) Negative (-) Inconclusive (±)
		24 Hours		48 Hours		72 Hours
		A	P	A	P	A	P
4380	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4381	E O	1 0	0 0	L1 0	0 0	L1 0	0 0	-
4382	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4383	E O	1 0	0 0	L1 0	0 0	L1 0	0 0	-
4384	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4385	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4386	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4387	E O	L1 0	0 0	L1 0	0 0	L1 0	0 0	-
4388	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4389	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4390	E O	L1 0	0 0	L1 0	0 0	L1 0	0 0	-
4391	E O	1 0	0 0	1 0	0 0	L1 0	0 0	-
4392	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4393	E O	L1 0	0 0	L1 0	0 0	L1 0	0 0	-
4394	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4395	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4396	E O	0 0	0 0	L1 0	0 0	L1 0	0 0	-
4397	E O	0 0	0 0	0 0	0 0	0 0	0 0	-
4398	E O	L1 0	L1 0	L1 0	0 0	0 0	0 0	-
4399	E O	L1 0	0 0	L1 0	0 0	L1 0	0 0	-

L             Localised Dermal Reaction (restricted to a small area of the challenge site)

A            Anterior site, exposed to the test substance, 50% w/w in acetone

P            Posterior site, exposed to the test substance, 20% w/w in acetone

 

Freunds Treated Controls

Guinea Pig No	E=Erythema O=Oedema	Score
		24 Hours		48 Hours		72 Hours
		A	P	A	P	A	P
4400	E O	0 0	0 0	0 0	0 0	0 0	0 0
4401	E O	0 0	0 0	0 0	0 0	0 0	0 0
4402	E O	L1 0	L1 0	L1 0	L1 0	L1 0	L1 0
4403	E O	0 0	0 0	0 0	0 0	0 0	0 0
4404	E O	1 0	0 0	1 0	0 0	1 0	0 0
4405	E O	L1 0	L1 0	L1 0	L1 0	0 0	L1 0
4406	E O	0 0	0 0	0 0	0 0	L1 0	0 0
4407	E O	0 0	0 0	L1 0	0 0	L1 0	0 0
4408	E O	1 0	0 0	1 0	0 0	1 0	0 0
4409	E O	L1 0	0 0	L1 0	0 0	0 0	0 0

L             Localised Dermal Reaction (restricted to a small area of the challenge site)

A            Anterior site, exposed to the test substance, 50% w/w in acetone

P            Posterior site, exposed to the test substance, 20% w/w in acetone

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The dermal reactions observed in the test animals were considered to be similar to or less marked than the maximum reactions noted in the control group animals. The test substance did not produce any evidence of delayed contact hypersensitivity.

Executive summary:

The sensitisation of the substance was measured by use of the Magnusson and Kligman hypersensitivity study using 20 test and 10 control guinea pigs. Under the conditions of the test, the test substance was considered to exhibit reactions of no greater severity than the control and the substance is considered to ne non-sensitising.