Stearic acid, esters with methyl α-D-glucoside

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: - Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

May 12, 1981

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

other: Pirbright white

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: no data
- Weight at study initiation: 268 - 339 g
- Housing: collective housing up to a maximum of 5 animals per cage (Macrolon type IV)
- Diet: ad libitum, Ssniff-G (Alleindiat für Meerschweinchen), Ssniff'Spezialdiaten GmbH, Soest/Westfalen, Germany
- Water: ad libitum, drinking water as for human consumption
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5 +/- 3.5
- Humidity (%): 50 - 85
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): artificial lighting (120 lux) from 7.00 a.m. -7.00 p.m.

Route:

intradermal and epicutaneous

Vehicle:

other: aqua ad injectabilia/petrolatum

Concentration / amount:

Range finding study:
Intradermal injection: 5 %
Dermal application: 25 %

Main study:
Intradermal injection: 5 %
Epicutaneous: 25 % (pretreated with 10 % sodium lauryl sulfat in petrolatum)
Challenge: 25 %

Route:

epicutaneous, occlusive

Vehicle:

other: aqua ad injectabilia/petrolatum

Concentration / amount:

Range finding study:
Intradermal injection: 5 %
Dermal application: 25 %

Main study:
Intradermal injection: 5 %
Epicutaneous: 25 % (pretreated with 10 % sodium lauryl sulfat in petrolatum)
Challenge: 25 %

No. of animals per dose:

Range finding study: 2 animals
Main study: 20 test, 20 control animals

Details on study design:

RANGE FINDING TESTS:
Intradermal Injection
The test article was diluted with water and Freund's complete adjuvant (FCA; Sigma, Deisenhofen, Germany) to give a final concentration of 5 %. If this concentration produced severe systemic toxicity, local necrosis or ulceration, it was reduced accordingly. Two animals were employed, skin reactions being recorded 48 h after treatment.

Dermal Application
The solid test article was incorporated in petrolatum to provide a final concentration of 25 % (w/v); if this concentration proved immoderately irritating, it was reduced accordingly. A closed patch exposure was effected by means of an occlusive bandage. Two animals were employed for each concentration tested and skin reactions were recorded 48 h post application.

MAIN STUDY
A. INDUCTION EXPOSURE

FIRST STAGE (intradermal injection, day 0)
- an area of 4 x 6 cm over the shoulders was clipped short with electric clippers and cleaned with 70 % (v/v) ethanol. Three pairs of intradermal injections were then made symmetrically in two rows on either side of the spine:
- No. of exposures: 3 pairs
- Test groups:
1. 0.1 ml FCA (diluted 1 : 2 in water)
2. 0.1 ml test article (final concentration: 5 % )
3. 0.1 ml test article emulsified in FCA (final concentration: 5 % )
- Control group:
1. 0.1 ml FCA (diluted 1 : 2 in water)
2. 0.1 ml vehicle (undiluted)
3. 0.1 ml vehicle (diluted 1 : 2 with FCA)
- Site: two rows on either side of the spine

SECOND STAGE (day 7)
- The same area was clipped and cleaned again.
- Because the test article was non-irritating at all tested concentrations, the clipped area was pretreated with 10 % sodium laurylsulfat (SLS) in petrolatum.
- 24 hours later, the test article was spread in a thick layer (to saturation) over a 2 x 4 cm patch (gauze).
- The latter was firmly secured over the previous injection sites by an occlusive dressing for 48 h.
- Concentration: based on the results of the pilot study the test article concentration was 25 %.
- Control animals: received a patch loaded with the vehicle alone.

B. CHALLENGE EXPOSURE (day 21)
- Exposure period: 24 h
- Site: 5 x 5 cm clipped and shaved area on each flank (test article was applied to the left flank and the vehicle to the right)
- Concentrations: 25 %, the maximal non-irritating concentration of the test article
- Dressing: occlusive, if necessary, the skin was cleaned with 70 % ethanol 21 h after removal of the patch.
- Evaluation (hr after challenge): 24 and 48 h


GRADING
- according to Magnusson and Kligman

Challenge controls:

Challenge exposure in control: 25 % of test substance

Positive control substance(s):

yes

Remarks:

2,4 dinitrochlorobenzene

Positive control results:

The last periodic use of a positive control substance (2,4 dinitrochlorobenzene) with the acceptable level of response in the test animals was performed on April 5, 1990.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no observations

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no observations.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no observations

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no observations.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no observations

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no observations.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no observations

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no observations.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: other: CLP, EU GHS (Regulation (EC) No 1272/2008)

Conclusions:

In this study, Stearic acid, esters with methyl α-D-glucoside (a.i. 100 %, according to producer information), is not a dermal sensitizer.

Executive summary:

In a dermal sensitization study according to OECD TG 406 with Stearic acid, esters with methyl α-D-glucoside (100 % a.i., according to producer information), Pirbright white guinea pigs were tested using the method of Magnusson and Kligman. Positive control substance was 2,4 dinitrochlorobenzene.

For intradermal induction a concentration of 5 % was used. The test concentration used for dermal induction (25 %) was non-irritating. However, 7 days after first intradermal induction the test site was pretreated with 10 % sodium laurylsulfat in petrolatum in order to create a local irritation. 24 hours later a 25 % dilution of the test substance was applied and covered by occlusive dressing for 48 hours. The same non-irritating test substance concentration (25 %) was used for challenge procedure. 

According to OECD guideline 406 a pretreatment with sodium lauryl sulphate is recommended, if the test substance is not a skin irritant. Thus, it can be assumed that including the pretreatment with the promoter substance sodium lauryl sulphate the induction procedure was sufficient to induce a potential allergic sensitisation reaction and the study is judged as valid.

At challenge no visible changes of the treated skin sites (no erythema and no edema) were observed in test or control animals at any time point.

  

In this study Stearic acid, esters with methyl α-D-glucoside (a.i. 100 %, according to producer information), is not a dermal sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a dermal sensitization study according to OECD guideline 406 with Stearic acid, esters with methyl α-D-glucoside (100 % a.i., according to producer information), Pirbright white guinea pigs were tested using the method of Magnusson and Kligman. Positive control substance was 2,4 dinitrochlorobenzene. For intradermal induction a concentration of 5 % diluted in water was used. The test concentration used for dermal induction (25 %) was non-irritating. However, 7 days after first intradermal induction the test site was pretreated with 10 % sodium lauryl sulfat in petrolatum in order to create a local irritation. 24 hours later a 25 % dilution of the test substance was applied and covered by occlusive dressing for 48 hours. The same non-irritating test substance concentration (25 %) was used for challenge procedure. 

According to OECD guideline 406 a pretreatment with sodium lauryl sulphate is recommended, if the test substance is not a skin irritant. Thus, it can be assumed that including the pretreatment with the promoter substance sodium lauryl sulphate the induction procedure was sufficient to induce a potential allergic sensitisation reaction. At challenge no visible changes of the treated skin sites (no erythema and no edema) were observed in test or control animals at any time point.

In a dermal sensitization study according to Magnusson and Kligman (OECD 406) performed with Isostearic acid, esters with methyl α-D-glucoside similar effects were observed. Based on the results of the pilot study, for the intradermal and epicutaneous induction procedure test substance concentrations of 0.5 % and 75 % in sesame oil were used, respectively. The concentration for challenge procedure was 15 % in sesame oil. Slight skin reactions were observed after induction, whereas at challenge no visible changes of the treated skin sites (no erythema and no edema) were observed in test or control animals at any time point. 

In conclusion there is no evidence for a skin sensitization potential of Stearic acid, esters with methyl α-D-glucoside from available studies. Likeweise sensitization properties of Stearic acid, esters with methyl α-D-glucoside and Isostearic acid, esters with methyl α-D-glucoside are observed, covering the expected similar toxicological profile of both substances as result of structural similarity.

Migrated from Short description of key information:
Not sensitising in the Guinea Pig Maximisation Test (OECD TG 406)

Justification for selection of skin sensitisation endpoint:
Data from GLP compliant skin sensitisation studies according to OECD guideline 406 (RL1) are available for the substance itself and the read-across substance Isostearic acid, esters with methyl α-D-glucoside.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Due to the low vapour pressure of Stearic acid, esters with methyl α-D-glucoside, the absence of skin and mucosal irritation and missing indications for skin sensitisation, a respiratory sensitisation potential of the test substance can practically be excluded.

Migrated from Short description of key information:
There are no indications for a sensitising potential of Stearic acid, esters with methyl α-D-glucoside from skin sensitisation studies.

Justification for classification or non-classification

Based on the results of the dermal sensitization study according to OECD guideline 406 there is no need for classification of Stearic acid, esters with methyl α-D-glucoside according to Directive 67/548/EEC as well as GHS Regulation EC No 1272/2008 with respect to skin sensitisation. No labelling is required.

On the basis of absence of skin and mucosal irritation, skin sensitisation and the very low vapour pressure of the test substance there is no need to classify the test substance with respect to respiratory sensitisation.