Resinoid of Liquidambar styraciflua (Hamamelidaceae) obtained from exudate by organic solvents extraction

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1995

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Remarks:

Those in vivo data have been considered sufficient, together with QSARs predictions on the main constituant, to classify the registered substance without further testing using a weight of evidence approach.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Identification of New Allergenic Constituents and Proof of Evidence for Coniferyl Benzoate in Balsam of Peru

Author:

Hausen

Year:

1995

Bibliographic source:

American Journal of Contact Dermatitis, Vol 6, N o 4 (Decem ber), 1995: p p 199-208

Reference 2

Reference Type:

publication

Title:

Studies on the sensitizing capacity of imidazole and triazole derivatives. Part lI.

Author:

Hausen BM, Angel M

Year:

1992

Bibliographic source:

Am J Contact Dermatitis 3:95-101

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Sensitization was performed with Cinnamyl Cinamate according to a modified Freund's complete adjuvant technique (Guinea pigs modified FCA method). The method was developed from Freund's complete adjuvant test (FCAT) and the guinea pig maximisation test (GPMT) in order to determine the sensitizing capacity of medium and weak allergens.
- Short description of test conditions:
Induction by 6 intradermal injections on day 1, day 5 and day 9 of Cinnamyl cinnamate dissolved in FCA and physiologicals aline.
Topical challenge on day 20 by open application. The challenge doses were 3 and 10% Cinnayl cinnamate in acetone.
Reading at 24, 48 and 72 hours.
The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong.
- Parameters analysed / observed: Skin irritation. Scoring of the response 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong

GLP compliance:

not specified

Type of study:

other: modified Freund's complete adjuvant method

Justification for non-LLNA method:

At the time of study completion (1995), the LLNA OECD test method was not adopted.

Test material

Test material information

Constituent 1

Reference substance name:

Cinnamyl cinnamate

EC Number:

204-566-1

EC Name:

Cinnamyl cinnamate

Cas Number:

122-69-0

Molecular formula:

C18H16O2

IUPAC Name:

3-phenylprop-2-enyl 3-phenylprop-2-enoate

Test material form:

not specified

Details on test material:

- Purchased (ICN, NY)
- Lot/Batch n°: not reported
- Purity: not reported

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Pirbright white strain

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: not reported
- Females (if applicable) nulliparous and non-pregnant: not specified
- Age at study initiation: ot reported
- Weight at study initiation: 280 to 350 g
- Housing: 3 to a cage
- Diet (e.g. ad libitum): yes, pellets
- Water (e.g. ad libitum): yes
- Acclimation period: not reported

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 to 24 °C
- Humidity (%): 50 to 55 %
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 10 hours light
- IN-LIFE DATES: not reported

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal

Vehicle:

other: Freund's complete adjuvant (FCA) + physiological saline (1:1)

Concentration / amount:

15 mg of Cinnamyl cinnamate in 8 mL of solvent

Day(s)/duration:

6 intradermal injections on day 1, 5 and 9.

Adequacy of induction:

not specified

Challenge

Challenge 1

No.:

#1

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

3%

Day(s)/duration:

Eleven days after induction

Adequacy of challenge:

highest non-irritant concentration

Challenge 2

No.:

#2

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

10%

Day(s)/duration:

Eleven days after induction

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: determination of irritancy
Ten guinea pigs were treated with the emulsion of FCA and physiological saline but without the tested material. They served also to determine patterns of irritation. One day before challenge, these animals were tested by applying different molar concentrations of test material to the right flank (0.1, 0.3 and 1.0 mol). The results were read after 24 hours.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Induction by 6 intradermal injections on day 1, day 5 and day 9 of Cinnamyl cinnamate dissolved in FCA and physiologicals aline.
- Test groups: yes
- Control group: see range finding test
- Concentrations: 15 mg of Cinnamyl cinnamate in 8 mL of solvent

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: Day 20 (eleven days following induction)
- Exposure period: open application
- Site: clipped and shave flank of the animals
- Concentrations: 3 and 10% in acetone
- Evaluation (hr after challenge): 24, 48 and 72 hours

OTHER:
The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong.

Challenge controls:

Not reported

Positive control substance(s):

not specified

Results and discussion

Positive control results:

Not applicable

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Group:

test chemical

Dose level:

3% in acetone

Total no. in group:

10

Clinical observations:

not reported

Remarks on result:

positive indication of skin sensitisation

Remarks:

detailed results not reported

Results 2

Key result

Reading:

1st reading

Group:

test chemical

Dose level:

10 % in acetone

Total no. in group:

10

Clinical observations:

not reported

Remarks on result:

positive indication of skin sensitisation

Remarks:

detailed results

Results 3

Reading:

1st reading

Group:

negative control

Dose level:

Acetone

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

not reported

Remarks on result:

not measured/tested

Remarks:

No negative control reported in the available public data

Results 4

Reading:

1st reading

Group:

positive control

Dose level:

Not reported

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

not reported

Remarks on result:

not measured/tested

Remarks:

No positive control reported in the available public data

Any other information on results incl. tables

Mean response at 3 % (24, 48 and 72h after challenge) = 0.10

Mean response at 10 % (24, 48 and 72h after challenge) = 0.47

Cinnamyl cinnamate was concluded as weak sensitiser

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Under the test conditions, Cinnamyl cinnamate, the main constituent of the registered substance, is classified as sensitiser category 1 according to Regulation (EC) No. 1272/2008 (CLP) and to the GHS. The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, the registered substance is classified as a skin sensitiser Cat. 1 without further testing according to the Regulation (EC) No 1272/2008.

Executive summary:

Sensitization was performed with Cinnamyl Cinamate according to a modified Freund's complete adjuvant (FCA) test method. The method was developed from Freund's complete adjuvant test (FCAT) and the guinea pig maximisation test (GPMT) in order to determine the sensitizing capacity of medium and weak allergens.

Ten female albino Guinea pigs of the Pirbright white strain were treated as follows: Induction by 6 intradermal injections on day 1, day 5 and day 9 with Cinnamyl cinnamate dissolved in FCA and physiologicals aline (1:1) (15 mg in 8 mL). Topical challenge on day 20 by open application. The challenge doses were 3 and 10% Cinnamyl cinnamate in acetone. Reading was done at 24, 48 and 72 hours.

The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong.

Cutaneous reactions were observed and considered to be sensitisation reactions. Mean responses of 0.1 at 3% and 0.47 at 10% indicate that Cinnamyl cinnamate is a weak sensitiser.

Mortality, body weight gain and clinical signs were not reported.

Under the test conditions, Cinnamyl cinnamate is considered as sensitiser.

The registered substance is a UVCB composed of several constituents and in that, it can be considered as a mixture according to the definition of the CLP Regulation. The decision logic for classification of mixtures from the ECHA Guidance on the Application of the CLP Criteria (2017) was used to determine the skin sensitising potential of the registered substance.

Cinnamyl cinnamate, the main constituent of the registered substance, was considered as a skin sensitiser in a in vivo study. The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, the registered substance is classified as a skin sensitiser Cat. 1 according to the Regulation (EC) No 1272/2008.

Those in vivo data have been considered sufficient, together with QSARs predictions on the main constituant, to classify the registered substance without further testing using a weight of evidence approach.