Dodecyl(2-hydroxy-3-sulphonatopropyl)dimethylammonium

Endpoint summary

Description of key information

A non-GLP skin sensitisation study has been conducted which was comparable to OECD 406. This showed the test material was not a skin sensitiser.

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:

From 16th March 2010 to 16th April 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

OECD 406 method but non GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

no

Remarks:

The original study is reported in Japanese; an English translation is available but is not considered to be GLP

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Test conducted much before the choice of LLNA is the first choice.

Specific details on test material used for the study:

-Lot No. : PAPS1x
-Purity: 31.4%

Species:

guinea pig

Strain:

Hartley

Sex:

not specified

Details on test animals and environmental conditions:

-Test system
1) Species, strain and microbiological control level
Guinea pigs, Hartley strain (Std: Hartley), clean

2) Supplier
Japan SLC, Inc. (3371-8, Koto-cho, Nishi-ku, Hamamatsu, Shizuoka)

3) Age in weeks and body weights
Animals were obtained at 4 weeks of age, acclimatized to laboratory conditions and quarantined for 7 days. Only well-grown animals in good physical condition were subjected to the study. The mean body weight was 337 g at the time of sensitization and 457 g at the time of challenge.

-Animal-rearing management
1) Rearing environment
Animals were kept under the following conditions: room temperature, 23±3ºC; relative humidity, 50±20%; ventilation frequency, 17 times/hour; lighting time, 12 hours (6:00 to 18:00)/day.

2) Rearing equipment and housing
Upon receipt, animals were housed 5 per cage in stainless-steel cages (W350XD400×H230 mm: Natsume Seisakusyo Co., Ltd.) placed on an automatic flush rack (Natsume Seisakusyo Co., Ltd.).

3) Feed and Drinking water
Animals were given free access to solid feed (RC4: Oriental Yeast Co., Ltd.) and municipal tap water filtered through a 5-μm cartridge filter.

Route:

intradermal and epicutaneous

Vehicle:

other: Saline for intradermaland and water for epicutaneous

Concentration / amount:

For intradermal: 0.1 and 0.2 w/w%
For epicutaneous: 1 w/w%

Day(s)/duration:

For epicutaneous: 48h

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

0.3, 0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

Day(s)/duration:

24h

No. of animals per dose:

A total of 23 animals (8 of the preliminary test group, 10 of the sensitization group and 5 of the control group) were subjected to the study.

Details on study design:

-Materials
1) Freund’s complete adjuvant (FCA:DIFCO LABORATORIES, Lot No.8353847)
2) Physiological saline (Japanese pharmacopoeia (JP), Otsuka Pharmaceutical Factory Inc., Lot No. K9K74)
3) Distilled water for injection (Distilled water: JP, Otsuka Pharmaceutical Factory Inc., Lot No. K9K76)

-Test solutions and Preparation methods
The samples were prepared at the following concentrations (w/w%) (as an active ingredient concentration).
1) Preliminary test
(1) Test solutions used for intradermal administration
Concentration (%): 0.1, 0.5, 0.3, 0.2, 0.1, 0.05 with vehicle as Physiological saline
 
(2)Test solutions used for occlusive-patch application
Concentration (%): 0.05, 0.1, 0.3, 0.5,1, 3 with vehicle as Distilled water

2) Test solutions used for intradermal sensitization
a: 1:1(v/v) emulsion of FCA and physiological saline
b: 0.1% solution (vehicle: physiological saline, state: solution)
c: 0.2% solution (vehicle: physiological saline, state: solution), 1:1(v/v) emulsion with FCA
d: Physiological saline

3) Test solutions used for epicutaneous sensitization
Sensitization group: 1% solution (vehicle: distilled water, state: solution)
Control group: Distilled water

4) Test solutions used for challenge
Concentration (%): 0.005, 0.01, 0.03, 0.05,0.1, 0.3 with vehicle as Distilled water

-Study methods
1) Preliminary test
(1) Intradermal administration
Primary skin irritation was tested to establish the concentrations for intradermal sensitization.
The injection site was the left flank of animals, and 0.1 mL each of the test solutions for intradermal administration was injected.

(2) Occlusive-patch application
Primary skin irritation was tested to establish the concentrations for contact sensitization and challenge.
Animals of the FCA emulsion treatment group (0.1 mL each of FCA emulsion was intradermally injected symmetrically into 4 sites of the left and right dorsal back region of animals one week before occlusive patch application) were subjected to the study. The application site was the left and right flanks of animals. The fabric of a tape for a patch test was impregnated with 0.05 mL each of test solutions for occlusive patch application, and a 24-hour occlusive-patch test was performed. The application sites were varied among the animals so that the reaction might be averaged among the application sites.

2)Sensitization method
(1) Intradermal sensitization
The injection site was the dorsal neck region. On Day 0, 0.1 mL each of the test solutions for intradermal sensitization was injected into the left and right dorsal neck regions (two sites) of animals of the sensitization group in the following order from the front: a, b and c, and of animals of the control group in the following order from the front: a, d and a (the injection space between the test solutions for intradermal sensitization, a and b and between a and d was narrowed).

(2) epicutaneous sensitization
Seven days after the start of sensitization, the intradermal injection site of animals in the sensitization group was covered with a 2×4 cm lint fabric (Nishio Eisei Zairyo KK) that was impregnated with 0.2 mL of the test solution for contact sensitization using the impermeable tape (Blenderm: 3M company) and elastic, adhesive bandage (Silkytex: Alcare co.) by the 48-hour occlusive patch test method. In the control group, animals were treated in the similar manner using distilled water.

3) Challenge method
Twenty-one days after the start of sensitization, an occlusive challenge patch was applied for 24 hours. The application site was the left and right flanks of animals, and a tape for a patch test (small size: Torii Pharmaceutical Co., Ltd.), the fabric of which was impregnated with 0.05 mL each of the test solutions for challenge, was applied. In addition, for securing dressings, the tape for a patch test was secured with adhesive sponge tape (Microfoam: 3M company) and elastic adhesive bandage. The application sites were varied among the animals so that the reaction might be averaged among the application sites.

4) Judgment criteria
In the preliminary test, skin reactions after intradermal administration were read 24, 48 and 72 hours after administration based on the following criteria (1). In addition, skin reactions after occlusive-patch application and challenge application were read 3, 24 and 48 hours after removal of the patch according to Draize scoring criteria described in (2) in the preliminary test.

(1) Judgment criteria for skin reactions after intradermal administration
- : 0: No reaction
± : 1: Very slight erythema
+ : 2: Well-defined erythema
+ + : 3: Well-defined erythema with edema
+ + + : 4: Eschar formation, necrosis
(2) Judgment criteria for skin reactions after occlusive-patch application and challenge application (occlusive-patch application) (Draize’s method)

0: No erythema
1: Very slight erythema (barely perceptible)
2: Well-defined erythema
3: Moderate to severe erythema
4: Severe erythema (beet redness) to slight eschar formation (injuries in depth)

0: No edema
1: Very slight edema (barely perceptible)
2: Slight edema (edges of area well defined by definite raising)
3: Moderate edema (raised approximately 1 mm)
4: Severe edema (raised more than 1 mm and extending beyond the area of exposure)
5) Average reaction strength
Scores for erythema, eschar formation and edema formation were divided by the number of animals and added.
 

Positive control substance(s):

no

Key result

Reading:

1st reading

Hours after challenge:

27

Group:

test chemical

Dose level:

0.3 w/w%

No. with + reactions:

3

Total no. in group:

10

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.3 w/w%

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

0.3 w/w%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

1st reading

Hours after challenge:

27

Group:

test chemical

Dose level:

0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

1st reading

Hours after challenge:

27

Group:

negative control

Dose level:

0.3 w/w%

No. with + reactions:

2

Total no. in group:

5

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.3 w/w%

No. with + reactions:

1

Total no. in group:

5

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

1st reading

Hours after challenge:

27

Group:

negative control

Dose level:

0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Key result

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

negative control

Dose level:

0.3, 0.1, 0.05, 0.03, 0.01, and 0.005 w/w%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No abnormalities in clinical signs were observed, and normal body weight gain was noted during the sensitization and challenge phases of the study.

Reading:

other: Not tested

Hours after challenge:

0

Group:

positive control

Dose level:

Not tested

No. with + reactions:

0

Total no. in group:

0

Remarks on result:

not measured/tested

The challenge results (24 hours after removing the patches) are shown below. 

Sample		Concentration (%)	Solvent	Mean reaction intensity
				Sensitization group	Control groups
(1)	10-S-020	Act.0.3	Distilled water	0.2	0.2
(2)	10-S-020	Act.0.1	Distilled water	0	0
(3)	10-S-020	Act.0.05	Distilled water	0	0
(4)	10-S-020	Act.0.03	Distilled water	0	0
(5)	10-S-020	Act.0.01	Distilled water	0	0
(6)	10-S-020	Act.0.005	Distilled water	0	0

The above results indicate that the test article has no sensitization potential.

 

Interpretation of results:

other: not sensitising

Conclusions:

The study results indicate that the test substance has no sensitization potential.

Executive summary:

The skin sensitization potential of 10-S-020 was examined in guinea pigs according to the Guinea Pig Maximization Test method.

A total of 23 animals including 8 for the preliminary test, 10 for the sensitization group, and 5 for the control group were used.

The concentration of the active ingredient in the test article was 31.4%. All samples were prepared based on the concentration of the active ingredient.

For sensitization induction, the following 3 preparations were intracutaneously administered to the back of each guinea pig: (a) an emulsion as prepared by mixing an equal volume of the Freund’s complete adjuvant (FCA) and physiological saline; (b) 0.1% solution of the test article (solvent: physiological saline); and (c) emulsion as prepared by mixing an equal volume of a 0.2% solution of the test article (solvent: physiological saline) and FCA. On Day 7 after starting sensitization, a patch infiltrated with a 1% solution of the test article (solvent: distilled water) was applied to each intracutaneous administration site and covered for 48 hours. The animals in the control group were treated in the same mannerexceptthe use of the solvent at each sensitization induction point.

For challenge, a patch infiltrated with the challenge solution was applied to the left and right flanks on Day 21 and covered for 24 hours.

The challenge results (24 hours after removing the patches) are shown below.

Sample		Concentration (%)	Solvent	Mean reaction intensity
				Sensitization group	Control groups
(1)	10-S-020	Act.0.3	Distilled water	0.2	0.2
(2)	10-S-020	Act.0.1	Distilled water	0	0
(3)	10-S-020	Act.0.05	Distilled water	0	0
(4)	10-S-020	Act.0.03	Distilled water	0	0
(5)	10-S-020	Act.0.01	Distilled water	0	0
(6)	10-S-020	Act.0.005	Distilled water	0	0

The above results indicate that the test article has no sensitization potential.

 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The test article is not classified for skin irritation based on the skin sensitisation study based on OECD 406.