p-(dimethoxymethyl)anisole

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

Cited as Directive 84/449/EEC, B.6

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

p-(dimethoxymethyl)anisole

EC Number:

218-577-4

EC Name:

p-(dimethoxymethyl)anisole

Cas Number:

2186-92-7

Molecular formula:

C10H14O3

IUPAC Name:

1-(dimethoxymethyl)-4-methoxybenzene

Details on test material:

- Name of test material (as cited in study report): Anisaldehyddimethylacetal
- Batch No.: B405 (Kol 5160 SA)
- Purity: 94%
- Substance No.: 90/645
- Date of production: 24 Sep 1990
- Physical state: liquid, achromatic
- Storage: room temperature

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Lippische Versuchstierzucht, Hagemann GmbH & Co . KG, D-W4923 Extertal 1, FRG
- Strain: Pirbright White, Dunkin Hartley HOE DHPK [SPF-LAC] BÖ
- Weight at study initiation: 281 - 342 g
- Housing: 5 per cage (Makrolon, type IV)
- Diet (e.g. ad libitum): Kliba 341 .4 mm, Firma Klingentalmühle AG, CH-4303 Kaiseraugst, Switzerland; ad libitum
- Water (e.g. ad libitum): tap water, ad libitum; about 2 g of ascorbic acid per 10 l water was added to the drinking water twice a week)
- Acclimation period: At least 7 days before the beginning of the study in the laboratory for dermal toxicity


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: Olive Oil DAB 9 or Freund's adjuvant emulsified with 0 .9% aqueous NaCl-solution in a ratio of 1 : 1

Induction 2

Concentration / amount:

Intradermal Induction: 5%
Epicutanous inductionn: 100%
Challenge: 75%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: Olive Oil DAB 9 or Freund's adjuvant emulsified with 0 .9% aqueous NaCl-solution in a ratio of 1 : 1

Challenge 2

Concentration / amount:

Intradermal Induction: 5%
Epicutanous inductionn: 100%
Challenge: 75%

No. of animals per dose:

Test group: 10 animals
Control group: 5 animals

Details on study design:

RANGE FINDING TESTS:
For determination of the minimum irritant concentration and the maximum non-irritant concentration, the test substance was applied 2 times for 24 hours within a period of 96 hours on the flank of 4 animals per test concentration. Assessment of skin findings was performed about 24 and 48 h after the beginning of application according to Draize.


MAIN STUDY
A1. INDUCTION EXPOSURE: intradermal
- No. of exposures: 1x6 intradermal injections;
- Test groups: 10
- Control group: 5
- Site: shoulder
- Concentrations: 5%
- Evaluation (hr after induction): 24 h

A2. INDUCTION EXPOSURE: epicutanous
- No. of exposures: 1
- Test groups: 10
- Control group: 5
- Site: shoulder, same area as in the case of the previous intradermal application
- Patch: 2 x 4 cm filter paper strips were applied under an occlusive dressing (the bandage consist of rubberized linenpatches 4 x 4 cm from Russka
and Fixomull Stretch (adhesive fleece) from Beiersdorf AG)
- Frequency of applications: one week after intradermal induction
- Duration: 48 h
- Concentrations: 100%
- Evaluation (hr after induction): 48 h

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 21 days after intradermal induction
- Exposure period: 24 h
- Test groups: 10
- Control group: 5
- Site: intact clipped flank
- Patch: 2 x 4 cm filter paper strips were applied under an occlusive dressing (the bandage consist of rubberized linenpatches 4 x 4 cm from Russka
and Fixomull Stretch (adhesive fleece) from Beiersdorf AG)
- Concentrations: 75%
- Evaluation (hr after challenge): 24 and 48 h after the removal of the patch

Positive control substance(s):

yes

Remarks:

1-chlor-2,4-dinitro-benzol

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

75%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 75%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

75%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 75%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

75%

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: 75%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

75%

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: 75%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Any other information on results incl. tables

Results and clinical symptoms:

Intradermal induction:
After intradermal induction well-defined erythema and slight edema were 
observed at the injection sites of the control animals and the test animals,
at which only Freund's adjuvant/0.9 % aqueous NaCl-solution  (1:1) was applied.
The test substance preparation in olive oil DAB 9 caused well-defined erythema
and very slight edema in the test animals.  Necrotic skin changes and slight 
edema could be observed at the injection  sites of the test animals, which were 
applied with the test substance preparation in Freund's adjuvant/0.9 % aqueous 
NaCl-solution (1:1). The  control animals injected with olive oil DAB 9 
exhibited well-defined erythema.

Epicutaneous induction:
The percutaneous induction was only carried out in the test group, because the 
test substance was applied unchanged and thus no solvent was used. Necrotic 
skin changes, partially open could be observed in addition  to slight edema.


Challenge:
The number of animals with skin findings after the challenge (21 days  after 
intradermal induction) is summarized in the following table:

                75 % in olive oil    olive oil DAB 9
                   DAB 9
----------------------------------------------------
Control group 1      0/5                 0/5
Control group 2*  no application of      0/5
                    test substance
Test group           0/10                0/10
----------------------------------------------------
x/y: number of positive reactions/number of animals tested; readings 24 h  after
 removal of the patch
*: Control group 2 that had been intended for a potential 2nd challenge was not
 needed, since a 2nd challenge was not necessary on the basis of  the 
unambiguous results of the 1st challenge

The 48 hour readings were similar to the 24 hour readings, no findings  could be
 observed.

After the percutaneous challenge with the 75 % test substance preparation in 
olive oil DAB 9 no skin reactions could be observed neither in the control 
group 1 nor in the test group.
Olive oil DAB 9 which was applied as a vehicle did not cause any skin reactions 
in all animals.