N,N-dimethyl-3-(octadecyloxy)propylamine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

From October 22, 2001 to March 26, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test was conducted way before the choice of LLNA is the first choice.

Test material

Test material information

Constituent 1

Reference substance name:

N,N-dimethyl-3-(octadecyloxy)propylamine

EC Number:

241-516-8

EC Name:

N,N-dimethyl-3-(octadecyloxy)propylamine

Cas Number:

17517-01-0

Molecular formula:

C23H49NO

IUPAC Name:

dimethyl[3-(octadecyloxy)propyl]amine

impurity 1

Reference substance name:

Octadecan-1-ol

EC Number:

204-017-6

EC Name:

Octadecan-1-ol

Cas Number:

112-92-5

Molecular formula:

C18H38O

IUPAC Name:

octadecan-1-ol

impurity 2

Reference substance name:

Unknown impurities

IUPAC Name:

Unknown impurities

additive 1

Reference substance name:

Lactic acid

EC Number:

200-018-0

EC Name:

Lactic acid

Cas Number:

50-21-5

Molecular formula:

C3H6O3

IUPAC Name:

2-hydroxypropanoic acid

additive 2

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

Test material form:

liquid

Details on test material:

Lactic acid solution was added to neutralize the test substance.

Specific details on test material used for the study:

Lactic acid solution was added to neutralize the test substance because this test substance posesses skin corrosion potentials. To reduce the skin corrosion/irritation potential so that the skin sensitization potential was accurately evaluated, the lactic acid solution was added.

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

-Test system
1) Supplier and breeding
Japan SLC, Inc. (3371-8, Koto-cho, Nishi-ku, Hamamatsu, Shizuoka), SPF, Closed colony

2) Number of animals
Pre-test: 5 for intradermal and 5 for epicutaneous, Main test: 21

3) Age in weeks
Pre-test: 4 weeks of age, Definitive test: 4 weeks of age.

4) Body weights
Pre-test: 266-304 g (obtained), 296-326 g (tested), Definitive test: 259-286 g (obtained), 299-327 g (tested),

5) Condition of animals
During the each test period, there was no sign of abnormity for tested animals.


-Animal rearing management
1) Acclimation and quarantine
Animals were acclimatized to laboratory conditions for 6 days and quarantined. Only well-grown animals in good physical condition were subjected to the study.

2) Rearing environment
Animals were kept under the following conditions: room temperature, 23±3ºC; relative humidity, 50±10%; ventilation frequency, 17 times/hour; lighting time, 12 hours (6:00 to 18:00)/day.

3) 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.).

4) 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.

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: Saline for intradermaland and water for epicutaneous

Concentration / amount:

For intradermal: 0.01 a.i. w/w%
For epicutaneous:0.5 a.i. w/w%

Day(s)/duration:

For epicutaneous: 48h

Adequacy of induction:

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

Challenge

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

0.1, 0.05, 0.03, 0.01, 0.005, 0.003 a.i. w/w%

Day(s)/duration:

24h

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10 of the sensitization group and 10 of the control group were subjected to the main study. 5 of the intradermal and 5 of the epicutaneous were subjected to the pre-study.

Details on study design:

-Materials
1) Freund’s complete adjuvant (FCA:DIFCO LABORATORIES, Lot No. 147436)
2) Physiological saline (Otsuka Pharmaceutical Factory Inc., Lot No. K0L73)
3) Distilled water for injection (Otsuka Pharmaceutical Factory Inc., Lot No. K1A80)

-Test solutions and preparation methods for the pre-test
The samples were prepared at the following concentrations (w/w%) (as an active ingredient concentration).
1) Test solutions used for intradermal administration
Concentration (%): 3, 1, 0.5, 0.3, 0.1, 0.05, 0.03, 0.01, 0.005, 0.003 with vehicle as physiological saline.
The injection site was the flank of animals, and 0.1 mL each of the test solutions for intradermal administration was injected.
 
2) Test solutions used for occlusive-patch application
Concentration (%): 5, 3, 1, 0.5, 0.3, 0.1 with vehicle as distilled water.
Animals of the FCA emulsion treatment group (0.1 mL each of FCA emulsion was intradermally injected one week before occlusive patch application) were subjected to the study. The application site was the flank 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.

-Test solutions and preparation methods for the main test
1) Test solutions used for intradermal and epicutaneous sensitization
a: 1:1(v/v) emulsion of FCA and physiological saline
b: 0.01% solution (vehicle: physiological saline)
c: 0.02% solution (vehicle: physiological saline), 1:1(v/v) emulsion with FCA
d: Physiological saline
e: 0.5% solution (vehicle: distilled water)
f: Distilled water

2) Intradermal and epicutaneous sensitization
(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 (e) 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 (f).

3) Challenge method
(1)Test solutions used for challenge (w/w%) (as an active ingredient concentration).
Concentration (%): 0.1, 0.03, 0.01, 0.005, 0.003 with vehicle as distilled water

(2)Twenty-one days after the start of sensitization, an occlusive challenge patch was applied for 24 hours. The application site was the flank 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
Skin reactions after challenge application (occlusive-patch application) were read 24 and 48 hours after removal of the patch. Judgment criteria for skin reactions are following (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)

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.1, 0.05, 0.03, 0.01, 0.005, 0.003 a.i. w/w%

No. with + reactions:

0

Total no. in group:

10

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

0.1, 0.05, 0.03, 0.01, 0.005, 0.003 a.i. w/w%

No. with + reactions:

0

Total no. in group:

10

Results 3

Key result

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.1, 0.05, 0.03, 0.01, 0.005, 0.003 a.i. w/w%

No. with + reactions:

0

Total no. in group:

10

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

Dose level:

0.1, 0.05, 0.03, 0.01, 0.005, 0.003 a.i. w/w%

No. with + reactions:

0

Total no. in group:

10

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

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

Executive summary:

The skin sensitization potential of N,N-dimethyl octadecyloxy propylamine (neutralized by lactic acid) was examined in guinea pigs according to the Guinea Pig Maximization Test method.

 

For sensitization induction, the following 3 preparations (0.1 mL each of the test solutions) were intracutaneously administered to the left and right dorsal neck regions (two sites) 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) 0.01 a.i. (w/w) % solution of the test article (solvent: physiological saline); and (c) emulsion as prepared by mixing an equal volume of a 0.02 a.i. (w/w) % solution of the test article (solvent: physiological saline) and FCA. On Day 7 after starting sensitization, a patch infiltrated with a 0.5 a.i. (w/w) % 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 manner except the use of the test substance at each sensitization induction point. Instead of the test substance, distilled water was used for the control group.

 

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 test concentrations were 0.1, 0.05, 0.03, 0.01, 0.005, 0.003 a.i. (w/w) % with distilled water as a solvent.

 

No skin reaction was observed for both the treated and the control groups. Therefore the study results indicate that the test substance has no sensitization potential.