Benzoic acid, 4-hydroxy-, 1,1'-(2-methyl-1,4-phenylene) ester

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: GLP and guideline study

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)

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japan MAFF guideline, 59 Noh San No. 4200, January 28, 1985

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

When this study was performed, the OECD testing guideline for the LLNA did not yet exist.

Test material

Test material information

Constituent 1

Reference substance name:

4-(4-hydroxybenzoyloxy)-3-methylphenyl 4-hydroxybenzoate

EC Number:

601-643-5

Cas Number:

119959-84-1

Molecular formula:

C21H16O6

IUPAC Name:

4-(4-hydroxybenzoyloxy)-3-methylphenyl 4-hydroxybenzoate

Details on test material:

- Name of test material (as cited in study report): Bis-1,4-(p-Hydroxybenzoesaeure)-methylphenylendiester
- Physical state: solid
- Storage condition of test material: room temperature
- Analytical purity: 99.6% (HPLC)

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, Borchen, Germany
- Age at study initiation: Young adult animals
- Weight at study initiation: 369 - 432 g
- Housing: Stainless steel wire mesh cages with pIastic-coated grating, minimum floor area: 2000 cm; 5 animals per cage
- Diet: Kliba Labordiaet (Kaninchen-Meerschweinchen-Haltungsdiaet) ad libitum
- Water: Tap water ad libitum
- Acclimation period: 7 days before the beginning of the study

ENVIRONMENTAL CONDITIONS
- Temperature: 21- 25°C
- Humidity: 30 - 70%
- Photoperiod (hrs dark / hrs light): 12 h light and 12 h darkness

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: Paraffin highly liquid(intradermal) and Lutrol E 400 (epicutaneous)

Induction 2

Concentration / amount:

Intradermal induction: 5%
Epicutaneous induction: 25%
Challenge: 25%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: Paraffin highly liquid(intradermal) and Lutrol E 400 (epicutaneous)

Challenge 2

Concentration / amount:

Intradermal induction: 5%
Epicutaneous induction: 25%
Challenge: 25%

No. of animals per dose:

5 (per control group); 10 (test group)

Details on study design:

RANGE FINDING TESTS:
The concentrations of the test substance suitable for use in the main experiment were determined in a pretest. One 24-hour epicutaneous occlusive application was performed. No skin irritation was observed after application of 25% and 10% test substance preparations in Lutrol E 400 (24 and 48 hours after removal of the patches).
Applicability: It was possible to inject a 5% test substance preparation in paraffin or in Freund's adjuvant / 0.9% aqueous NaCI-solution (1 : 1) with a syringe. The concentration was weII-tolerated locally and systemically.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: two (intradermal and epicutaneous)
- Intradermal induction: 6 intradermal injections in groups of two per animal were given.
lnjections for the control groups: two injections each of 0.1 ml Freund's adjuvant without test substance emulsified with 0.9% aqueous NaCI-solution in a ratio of 1:1, two injections each of 0.1 ml of the undiluted vehicle, two injections each of 0.1 ml of a 50% formulation of the vehicle without test substance emulsified with Freund's adjuvant / 0.9% aqueous NaCI-solution (1:1)
Injections for the test group: two injections each of 0.1 ml Freund's adjuvant without test substance emulsified with 0.9% aqueous NaCI-solution in a ratio of 1: 1, two injections each of 0.1 ml of a test substance formulation in an appropriate vehicle at the selected concentration, two injections each of 0.1 ml Freund's adjuvant / 0.9% aqueous NaCI-solution (1: 1) with test substance at the selected concentration.
- Epicutaneous induction:
Epicutaneous induction was carried out one week after intradermal induction. 2x4 cm gauze patches containing the test substance formulation were applied to the skin of the shoulder under an occlusive dressing for 48 hours. 1 ml of the test substance formulation was applied to each animal. The control groups were treated analogously to the test group but only with the vehicle without the test substance.
- Site: Shoulder
- Concentrations: 5% (intradermal) and 25% (epicutaneous)

B. CHALLENGE EXPOSURE
The first challenge was performed 14 days after the epicutaneous induction. A second challenge was carried out one week after the first one.
2x2 cm gauze patches containing the test substance formulation were applied to the skin of the flank under an occlusive dressing. 0.5 ml of the test substance formulation was applied to each animal.
- 1st challenge: The test group and control group 1 were treated with the test substance formulation. Additionally, Lutrol E 400 was applied as a vehicle control. Control group 2 only received Lutrol E 400.
- 2nd challenge: The test group and control groups 1 and 2 were treated with the test substance formulation. Analogous to the challenge Lutrol E 400 was applied as a vehicle control.
Duration of exposure: 24 hours
Site of application:
1st challenge: Test substance formulation: right flank posterior; vehicle: left flank posterior
2nd challenge: Test substance formulation: left flank anterior; vehicle: right flank anterior
Readings: 24 and 48 h after the removal of the patch

Positive control substance(s):

no

Remarks:

A positive control (reliability check) with a known sensitizer is not included in this study. However, a separate study is performed twice a year in the laboratory.

Results and discussion

In vivo (non-LLNA)

Results

Reading:

other: 1st and 2nd challenge

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: other: 1st and 2nd challenge. . Hours after challenge: 48.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the results of this study it was concluded that the test substance does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test under the test conditions chosen.

Executive summary:

The test substance was tested for its sensitizing effect on the skin of the guinea pig in the Maximization Test based on the method of Magnusson and Kligman. The intradermal induction with 5% test substance preparations caused intense erythema and swelling in all test group animals. After the epicutaneous induction with a 25% test substance preparation in Lutrol E 400 incrustation, partially open (caused by the intradermal induction) could be observed in addition to moderate and confluent erythema and swelling in all test group animals. Two challenges were performed 14 and 21 days after the epicutaneous induction. The number of animals with skin findings after the 1st challenge and after the 2nd challenge is zero. Based on the results of this study and applying the evaluation criteria it was concluded that the test substance does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test under the test conditions chosen.