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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant, guideline study, available as unpublished report, no restrictions, fully adequate for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report date:
1994

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
438-530-3
EC Name:
-
Cas Number:
5343-44-2
Molecular formula:
C20H41NO
IUPAC Name:
N,N-di-tert-butyldodecanamide
Details on test material:
- Name of test material (as cited in study report): N,N-dibutyldodecanamide (HAEL no. 94-0003, KAN 905762, CIN 10005762)
- Physical state: light yellow liquid
- Analytical purity: not reported
- Impurities (identity and concentrations): not reported
- Lot/batch No.: 1093-002
- Expiration date of the lot/batch: not reported

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Crl:(HA)BR VAF/Plus
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Kingston, NY, USA
- Age at study initiation: 5-6 weeks
- Weight at study initiation: 284-410 g
- Housing:individually in suspended, stainless steel mesh cages
- Diet (e.g. ad libitum): Agway Prolab guinea pig diet ad libitum
- Water (e.g. ad libitum): mains water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 68-71°F
- Humidity (%): 46-55%
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

IN-LIFE DATES: From: 14 February 1994 To: 18 March 1994

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
corn oil
Concentration / amount:
5.0% for intradermal induction phase, 100% (as supplied) for topical induction and challenge phases.
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
corn oil
Concentration / amount:
5.0% for intradermal induction phase, 100% (as supplied) for topical induction and challenge phases.
No. of animals per dose:
20 test and 10 control animals
Details on study design:
RANGE FINDING TESTS:
-Intradermal injections: (2 guinea pigs used) 0.1, 1.0, 3.0 and 5.0% of test substance in corn oil and 0.1, 1.0, 3.0 and 5.0% of test substance in Freunds complete adjuvant (FCA): water (1:1)
-Topical application: (2 guinea pigs used) 100% test substance

MAIN STUDY
A. INDUCTION EXPOSURE
- intradermal induction (day 0): Hair was removed from th shoulder area of each guinea pig and 3 pairs of intradermal injections were made, each pair flanking the dorsal midline. For the test group, the three pairs of intradermal injections were as follows:
(1) 0.1 mL of a 5% preparation of the test material in corn oil (concentration determined in primary irritation screen)
(2) 0.1 mL of the FCA emulsion
(3) 0.1 mL of a 5% preparation of the test material in FCA emulsion (concentration determined in primary irritation screen)
For the control group, the three pairs of intradermal injections were as follows:
(1) 0.1 mL of corn oil
(2) 0.1 mL of the FCA Emulsion
(3) 0.1 mL of corn oil in FCA Emulsion (1:1)

- local irritation (day 6): Hair was removed from the shoulder area and application site of all animals (treated and control) painted with approximately 0.5 mL 10% sodium lauryl sulphate in petrolateum.

- topical induction (day 7): For the treated animals, a single application of 2.0-2.5 g of the neat test substance was applied to a 2.5 x 2.5 cm patch which was then placed onto the application site and held in place using an elastic bandage, for 48 hours. Controls were treated in an identical manner except that the patch was loaded with water.

B. CHALLENGE EXPOSURE
Hair was removed from an area (approximately 3.75 x 3.75 cm) on both flanks of all animals. A fully loaded patch (approximately 2.5 cm x 2.5 cm) with 100% test material was applied to the left flank of each animal (treated and control). A fully loaded patch (water only) was applied to the right flank of each animal. The patches were secured with elastic bandage wrapped around the torso. The patches were left in place for 24 hours. Approximately 24 and 48 hours after removal of the patches dermal erythema reactions were assessed using a 0-3 scale.
Positive control substance(s):
yes
Remarks:
2-Mercaptobenzothiazole (CAS No. 149-30-4)

Results and discussion

Positive control results:
2-mercaptobenzothiazole produced positive sensitisation responses in the method validation study.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
100%
No. with + reactions:
14
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 100%. No with. + reactions: 14.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
100%
No. with + reactions:
15
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 100%. No with. + reactions: 15.0. Total no. in groups: 20.0.
Reading:
rechallenge
Hours after challenge:
48
Group:
negative control
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Any other information on results incl. tables

In test animals, following challange at 100%, mild (grade 1) to moderate (grade 2) redness was seen in 14/20 sites at the 24 hour reading and in 15/20 sites at the 48 hour reading. No dermal responses were evident at the control sites for the 20 test animals previously induced with the test material or at either the test site or the control site for the 10 control animals.

Table: Maximisation test: Number of animals with signs of allergic skin reactions - See attached report                                                                  

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information
Conclusions:
N,N-dibutyldodecanamide was a sensitiser to guinea pig skin.
Executive summary:

N,N-dibutyldodecanamide was assessed for its skin sensitisation potential using the guinea pig maximisation test. 15 out of 20 guinea pigs, previously induced with N,N-dibutyldodecanamide elicited a dermal response 24 and/or 48 hours after challenge. There was no dermal response in any of the control animals. The net response was, therefore, 75% and N,N-dibutyldodecanamide is considered to be a skin sensitiser to the guinea pig.