N,N-dimethylacrylamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Near-guideline study, available as unpublished report, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

no

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

N,N-dimethylacrylamide

EC Number:

220-237-5

EC Name:

N,N-dimethylacrylamide

Cas Number:

2680-03-7

Molecular formula:

C5H9NO

IUPAC Name:

N,N-dimethylacrylamide

Details on test material:

- Name of test material (as cited in study report): NNDMA (N,N-dimethyl acrylamide)
- Physical state: clear liquid

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Elm Hill Breeding Labs, Chelmsford, MA
- Housing: group housed in suspended stainless steel caging with mesh floors. Litter paper was placed beneath the cages and was changed at least three times per week.
- Diet: Purina Guinea Pig Chow #5025, ad libitum
- Water: filtered tap water, ad libitum

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

water

Induction 2

Concentration / amount:

First induction: intadermal injection (0.1 ml):
50% v/v Complete Freund's Adjuvant mixture in distilled water
test substance as a 5% w/w mixture in distilled water
5% w/w mixture of test substance in Complete Freund's Adjuvant (50% v/v in distilled water)

Second induction: topical application:
25% w/w

Challenge:
25% w/w

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

water

Challenge 2

Concentration / amount:

First induction: intadermal injection (0.1 ml):
50% v/v Complete Freund's Adjuvant mixture in distilled water
test substance as a 5% w/w mixture in distilled water
5% w/w mixture of test substance in Complete Freund's Adjuvant (50% v/v in distilled water)

Second induction: topical application:
25% w/w

Challenge:
25% w/w

No. of animals per dose:

10 (test group)
5 (vehicle control)

Details on study design:

RANGE FINDING TESTS:
Based on these findings of preliminary irritation screens, the concentration selected for the intradermal induction was a 5% w/w solution in distilled water, and that selected for the topical induction which produced faint irritation was a 25% w/w mixture in distilled water. The HNIC (the highest concentiation that produced responses in four guinea pigs no more severe than two scores of 0.5 and two scores of zero) selected for the challenge phase was a 25% w/w mixture in distilled water.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Test groups: 10
- Control group: 5
- Site: suprascapular area
- Frequency of applications: once weekly
- Concentrations: 5 (intradermal injection) and 25% w/w (topical application, 48 hours)

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Exposure period: 24 h
- Test groups: 10
- Control group: 5
- Site: naive site on each right side of test and sham control animal
- Concentrations: 25% w/w
- Evaluation (hr after challenge): 24 and 48 h

Positive control substance(s):

yes

Remarks:

alpha-hexylcinnamaldehyde

Results and discussion

Positive control results:

Six of the ten positive control animals exhibited signs of a sensitisation response (faint to moderate erythema [1-2]) 24 and 48 hours after challenge patch removal. Very faint erythema (0.5) was noted for three, other sites at the 24 and 48 hour interval.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

5 of 10 animals showed very faint erythema (grade: 0.5)

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: 10.0. Clinical observations: 5 of 10 animals showed very faint erythema (grade: 0.5).

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

2 of 10 animals showed very faint erythema (grade: 0.5)

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: 10.0. Clinical observations: 2 of 10 animals showed very faint erythema (grade: 0.5).

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

1 of 5 animals showed very faint erythema (grade: 0.5)

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: 5.0. Clinical observations: 1 of 5 animals showed very faint erythema (grade: 0.5).

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

5

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: 5.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information