2,4-bis[(4-dodecylphenyl)azo]resorcinol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed journal.

Data source

Reference

Reference Type:

publication

Title:

Experimental study on skin sensitization potencies and cross-reactivities of hair-dye-related chemicals in guinea pigs

Author:

Zhenlin Xie et.al

Year:

2000

Bibliographic source:

Contact Dermatitis

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Magnusson & Kligman guinea pig maximization test (GPMT)

Principles of method if other than guideline:

To evaluate skin sensitization potential of the test chemical on guinea pigs

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Not specified

Test material

Test material information

Constituent 1

Reference substance name:

1-(4-(phenylazo)phenylazo)-2-naphthol

EC Number:

201-638-4

EC Name:

1-(4-(phenylazo)phenylazo)-2-naphthol

Cas Number:

85-86-9

Molecular formula:

C22H16N4O

IUPAC Name:

1-(4-(phenylazo)phenylazo)-2-naphthol

Test material form:

solid

Details on test material:

- Name of test material : 1-(4-(phenylazo)phenylazo)-2-naphthol
- Molecular formula : C22H16N4O
- Molecular weight : 352.3954 g/mol
-Smiles:c12c(\N=N\c3ccc(\N=N\c4ccccc4)cc3)c(ccc1cccc2)O
-InChI:1S/C22H16N4O/c27-21-15-10-16-6-4-5-9-20(16)22(21)26-25-19-13-11-18(12-14-19)24-23-17-7-2-1-3-8-17/h1-15,27H/b24-23+,26-25+
- Substance type: organic
- Physical state: solid powder
- Purity: 99%
- Impurities : approx 1%

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Nippon Bio Supp. Center, Tokyo
- Age at study initiation: 4 weeks
- Weight at study initiation: 300 – 350 g
- Housing: housed in groups of 3 in stainless steel wire-mesh cages
- Diet (e.g. ad libitum): solid diet ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22± 2°C
- Humidity (%): 55±5%
- Air changes (per hr): 15x/h
- Photoperiod (hrs dark / hrs light): 12 h daily

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

olive oil

Concentration / amount:

(1) 0.1 ml emulsified mixture of Freund’s complete adjuvant and saline (1:1);
(2) 0.1 ml of 0.1% chemicals in olive oil
(3) 0.1 ml of the 0.1% test substance in FCA and saline mixture (1:1).

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

0.5 g of 1.0% test chemicals in petrolatum

Day(s)/duration:

48 hours

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

Challenge

No.:

#1

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

0.03 ml

Day(s)/duration:

72 hours

Adequacy of challenge:

other: the highest soluble concentrations were used

No. of animals per dose:

Total=6

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3 injections
- Exposure period: no data
- Test groups: 6 animals
- Control group: not specified
- Site: 2x4 cm clipped neck
- Frequency of applications: not specified
- Duration: not specified
- Concentrations: 0.1 ml of 0.1% test material

B. INDUCTION EXPOSURE
- No. of exposures: not specified
- Day(s) of induction: on day 7
- Exposure period: 48 hrs
- Test groups: 6 animals
- Control group: not specified
- Site: 2x4 cm clipped neck

- Concentrations: 0.5 g of 1.0% test chemical

C. CHALLENGE EXPOSURE
- No. of exposures: not specified
- Day(s) of challenge: 1
- Exposure period: 72 hrs
- Test groups: 6 animals
- Control group: not specified
- Site: flank regions
- Concentrations: 0.03 ml in acetone
- Evaluation (hr after challenge): 48 h


OTHER: In order to enhance the sensitization, sodium lauryl sulfate 10% in petrolatum was applied on induction area for 24 h before the topical induction.

Challenge controls:

vehicle control used

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.03 ml in acetone

No. with + reactions:

0

Total no. in group:

6

Clinical observations:

In Sudan III-induced animals, no positive reaction was elicited at 0.1% concentrations

Remarks on result:

no indication of skin sensitisation

In vivo (LLNA)

Cellular proliferation data / Observations:

No positive reaction was elicited at 0.1% concentrations

Applicant's summary and conclusion

Interpretation of results:

other: Not sensitizing

Conclusions:

The skin sensitization potential of the test chemical was evaluated on 6 Female Hartley strain albino guinea pigs.
No positive reaction was elicited at the concentrations tested. Hence, the test chemical was considered to be not sensitizing to guinea pig’s skin.

Executive summary:

Magnusson & Kligman guinea pig maximization test (GPMT) was conducted on six Female Hartley strain albino guinea pigs to assess the dermal sensitization potential of the test chemical.

Induction treatment consisted of 3 intra-dermal injections and one topical induction. On day 0, a row of 3 injections of 0.1 ml test material emulsified mixture of Freund’s complete adjuvant and saline (1:1) in olive oil was given on each side of the 2x4 cm clipped neck . In order to enhance the sensitization, sodium lauryl sulfate 10% in petrolatum was applied on induction area for 24 h before the topical induction. On day 7, 0.5 g of 1.0% test chemicals in petrolatum were occlusively applied for 48 h. The samples were covered with lint pads which were lining with Blenderm tape.

The challenge treatment was given by open topical application. On day 21, the flank regions of the animals were clipped and shaved, and then 0.03 ml of test material in acetone was applied to the skin for 72 hrs. Observations were made 48 hrs after challenge. No positive reaction was elicited at the concentrations tested.

Hence, the test chemical was considered to be not sensitizing to guinea pig’s skin.