2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyoctadecan-2-yl]benzamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June-2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted 17 July, 1992

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

other: "Allergic Contact Dermatitis in the Guinea-Pig: Identification of Contact Allergens"

Version / remarks:

Magnusson B. Kligman A.M., 1970 published by C.C. Thomas, Springfield, Illinois, USA.

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A valid GPMT study conducted similar to guideline is available, which is reliable with restrictions and adequate for classification and labelling purposes. Potency estimation is not mandatory when existing guideline and GLP conforming data are available, which were conducted before the new annex of the REACH Regulation entered into force.
Moreover, no indication for skin sensitisation was observed in this study and thus, no dose response information is needed. As described in OECD guideline 406, the LLNA is able to detect reliably moderate to strong sensitisers. Because the test substance is unlikely to be a sensitiser, the GPMT was considered appropriate. For this reason and for reasons of animal welfare no additional LLNA was conducted.

Test material

Test material information

Constituent 1

Reference substance name:

2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyoctadecan-2-yl]benzamide

EC Number:

855-895-8

Cas Number:

212908-67-3

Molecular formula:

C27H47NO5

IUPAC Name:

2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyoctadecan-2-yl]benzamide

Test material form:

solid: particulate/powder

Details on test material:

Batch: K928/99/1/1/39
Purity: 97.4%

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- no information available
TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: the test substance was prepared in propylene glycol (w/w) prior to each treatment.
- Final preparation of a solid: 1 and 20%

In vivo test system

Test animals

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

propylene glycol

Concentration / amount:

Intradermal induction: 1 % (w/w) of the test item, in propylene glycol
Dermal induction: 20 % (w/w) of the test item, in propylene glycol

Day(s)/duration:

8

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Challenge

Route:

epicutaneous, occlusive

Vehicle:

propylene glycol

Concentration / amount:

Challenge: 20% (w/w) of the test item, in propylene glycol

Day(s)/duration:

3

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

Number of animals in the test group: 10
Number of animals in the negative control group: 5
Number of animals in the dose range finding study: 4

Details on study design:

The study procedure were based on the test methos described by Magnusson and Kligman, "Allergic Contact Dermatitis in the Guinea Pig - Identification of Contact Allergens". Based on a test substance pretest, propylene glycol was selected as the most suitable vehicle for Salicyloyl Phytosphingosine. Test substance concentrations selected for the Main study were based on the results of a preliminary study using four animals. In the main study, ten experimental animals were intradermally injected with a 1% concentration and epidermally exposed to a 20% concentration, while five control animals were similarly treated, but with the vehicle only. Since no signs of irritation were observed at the concentration selected for the epidermal induction, all animals were treated with 10% SDS appromimately 24 hours before the epidermal induction. Two weeks after the epidermal application all animals were challenged with a 20% test substance concentration and the vehicle. The challenge reactions were assessed 24 and 48 hours after bandage removal.

Challenge controls:

5 animals challenged in the same manner without induction

Positive control substance(s):

no

Results and discussion

Positive control results:

No information given.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

20%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no

Remarks on result:

no indication of skin sensitisation

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

20%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no

Remarks on result:

no indication of skin sensitisation

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0 %

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no

Remarks on result:

no indication of skin sensitisation

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0 %

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

MAIN STUDY

INDUCTION – READINGS

SKIN REACTIONS AFTER INTRADERMAL INJECTION

Animal Number	Intradermal injection (Day 3)			Epidermal exposure (Day 10), D
	A	B	C	Erythema	Oedema
Control	E3	N2	N6	0 a	0
51	E4	N5	N7	0 a	0
52	E3	N5	N6	0 a	0
53	E4	N4	N6	0 a	0
54	E3	N3	N7	0 a	0
55
Experimental:
56	E3	N6	N6	0 a	0
57	E3	N7	N2	0 a	0
58	E3	N7	N8	0 a	0
59	E3	N6	N6	0 a	0
60	E4	N6	N7	0 a	0
61	E4	N6	N7	0 a	0
62	E3	N6	N7	0 a	0
63	E4	N5	N7	0 a	0
64	E3	N6	N6	0 a	0
65	E4	N5	N7	0 a	0

 

A) Mixture of Freunds' Complete Adjuvant and water for injection

B) 1% test substance concentration (experimental); vehicle (control)

C) 1:1 Mixture of FDA and a 2% concentration (experimental) or vehicle (control)

D) 20% test substance concentration (experimental); vehicle (control)

a) small scabs

Skin effects intradermal injections:

E(.) Erythema (grade)

N(.) Signs of necrosis (mm in diameter)

 

 

 

 

 

 

 

CHALLENGE READINGS

Animal Number	Day 23		Day 24
	20%#	Vehicle*	20%#	Vehicle*
Control
51	0	0	0	0
52	0	0	0	0
53	0	0	0	0
54	0	0	0	0
55	0	0 a	0	0 a
Experimental:
56	0	0	0	0
57	0	0	0	0
58	0	0	0	0
59	0	0	0	0
60	0	0	0	0
61	0	0	0	0
62	0	0	0	0
63	0	0	0	0
64	0	0	0	0
65	0	0	0	0

 

#Test substance concentration

*Propylene glycol

a) bold spot

 

 

No visible change: 0

Discrete or patchy erythema: 1

Moderate and confluent redness: 2

Moderate redness and swelling: 3

Intense reddening and swelling: 4         

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions used in this study, no positive skin reactions were observed in any of the animals after the challenge exposure. The test item is therefore considered not to be a dermal sensitizer.

Executive summary:

In this skin sensitization study based on the test method described by Magnusson and Kligman, "Allergic Contact Dermatitis in the Guinea Pig - Identification of Contact Allergens", it was evaluated whether Salicyloyl Phytosphingosine induces skin hypersensitivity in guinea pigs after intradermal and epidermal exposure.

After assessment of the slightly irritating and the non-irritating test substance concentrations in a preliminary study, a main study was performed with the selected test substance concentrations. Ten animals were intradermally injected with a 1 % concentration and epidermally exposed to a 20 % concentration, while five control animals were treated similarly, but with the vehicle only. Immediately after epidermal exposure, the skin irritation was scored. Two weeks after the epidermal application all animals were challenged with test substance concentrations of 20%, and the vehicle propylene glycol. The challenge reactions were assessed 24 and 48 hours after bandage removal.

The epidermal exposure to Salicyloyl Phytosphingosine in the challenge phase resulted in no positive reactions.

Under the conditions of this study, Salicyloyl Phytosphingosine induced no skin sensitisation in guinea pigs and is therefore considered to be a non-sensitizer.