2-(dimethylamino)ethyl acrylate

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: GLP guideline study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Principles of method if other than guideline:

Method according to Magnusson and Kligman (J. Invest. Derm. 52: 268-276 (1969)).

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

2-(dimethylamino)ethyl acrylate

EC Number:

219-460-0

EC Name:

2-(dimethylamino)ethyl acrylate

Cas Number:

2439-35-2

Molecular formula:

C7H13NO2

IUPAC Name:

2-(dimethylamino)ethyl prop-2-enoate

Details on test material:

- Name of test material (as cited in study report): ADAME
- Purity: no impurities
- Physical state: colourless liquid
- Supplier: Norsolor (Group Orkem)
- Lot/batch No.: RN 107 - 26/05/88
- Storage condition of test material: + 4°C

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Shamrock Bio Service breeding centre
- Weight at study initiation: mean males 336±11 g, mean females 327±10 g
- Housing: individual housing in sterilizable polycarbonate cages (48 x 27 x 20 cm)
- Diet: certified pellet diet "Cobaye entretien référence 106" (U.A.R. 91360 Villemoisson sur Orge, France) ad libitum
- Water: filtered water ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3
- Humidity (%): 50±20
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

paraffin oil

Induction 2

Concentration / amount:

Intradermal induction: 0.5% TS in paraffin oil (0.1 ml)
Epicutaneous induction: 5% TS in paraffin oil (0.5 ml)
Epicutaneous challenge: 5% TS in paraffin oil (0.5 ml)

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Challenge 2

Concentration / amount:

Intradermal induction: 0.5% TS in paraffin oil (0.1 ml)
Epicutaneous induction: 5% TS in paraffin oil (0.5 ml)
Epicutaneous challenge: 5% TS in paraffin oil (0.5 ml)

No. of animals per dose:

Control group: 5 males and 5 females;
Test group: 10 males and 10 females

Details on study design:

- INDUCTION EXPOSURE (10 days)
Induction by intradermal route: On day 1, three doses of 0.1 ml were injected into each side of the spine on 4 x 2 cm of the scapular area using a needle. In the first set of injections, the animals of both groups received Freund's complete adjuvant at 50% in an isotonic injectable solution of 0.9% NaCl. In the second set of injections, the animals of the control group received the vehicle only while the animals of the treated group received the test substance at 0.5% suspended in the vehicle. The third set of injections was a mixed solution 50/50 (v/v) of Freund's complete adjuvant at 50% in an isotonic injectable solution of 0.9% NaCl and the vehicle given to the control animals, or the test substance at 0.5% in its vehicle to the treated animals.

Induction by cutaneous route: As the TS did not show any irritating characteristics at the concentration of 5% by cutaneous application under an occlusive dressing during the preliminary test, a local irritation was induced on day 8 by applying 0.5 ml of 10% sodium lauryl-sulphate in vaseline to the scapular region. On day 9, 0.5 ml of the vehicle in the control group or 0.5 ml of the TS at 5% in the treated group were applied to the scapular region of the animals and were held in contact with the skin for 48 hours by means of an occlusive dressing. One hour after removal of the occlusive dressing, the cutaneous reactions were recorded.

- REST PERIOD (15 days)

- CHALLENGE EXPOSURE
On day 26, the animals from both groups received an application of 0.5 ml o f the TS at the concentration of 5% in paraffin oil on an area of 4 cm² on the posterior right flank and 0.5 ml of the vehicle on the posterior left flank. This application was made using a sterile 1 ml glass syringe on an area of 4 cm² (2 x 2 cm). The TS was held in contact with the skin by a sterile 4 cm² Codex patch. An adhesive hypoallergic dressing and a plastic impermeable adhesive anallergic plaster were then placed around the animals' trunk. In order to avoid interference from any cutaneous reactions before and after the challenge application in 5 animals (ecchymoses before application of the TS) , the applications were performed on the intact sites of the flanks. Twenty-four and 48 hours after removal of the occlusive dressing, the flanks of the animals were observed in order to evaluate any cutaneous reactions. After the final scoring period, the animals were sacrificed and cutaneous samples were taken from the challenge application sites in all surviving animals. Due to the presence of "doubtful" macroscopic cutaneous reactions, an histological examination was performed on the cutaneous samples of the animals from the treated group.

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

5%

No. with + reactions:

19

Total no. in group:

19

Clinical observations:

very slight to well-defined erythema, moderate lesions in cutaneous samples

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 5%. No with. + reactions: 19.0. Total no. in groups: 19.0. Clinical observations: very slight to well-defined erythema, moderate lesions in cutaneous samples.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5%

No. with + reactions:

19

Total no. in group:

19

Clinical observations:

very slight to well-defined erythema, moderate lesions in cutaneous samples

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 5%. No with. + reactions: 19.0. Total no. in groups: 19.0. Clinical observations: very slight to well-defined erythema, moderate lesions in cutaneous samples.

Any other information on results incl. tables

One male from the treated group was found dead on day 9 without any clinical signs in the days prior to death. No further behavioural abnormalities were recorded in the other animals.

After the challenge cutaneous application, no reactions were observed on the left flank (vehicle) of the animals from the control and treated groups. On the right flank (test substance at 5 % in the vehicle) no reactions of irritation were noted in the control animals. Slight to moderate macroscopic reactions (very slight to well-defined erythema) were noted after 24 and 48 hours in all animals from the treated group. The microscopic examination of the cutaneous samples showed moderate lesions in all animals from the treated group. The lesions consisted mainly of hyperkeratosis, acanthosis and mononucleated cell infiltration.

Scoring of the cutaneous reactions:

Group	Sex	Erythema score	Scoring of the cutaneous parameters
			24 hours		48 hours
			LF	RF	LF	RF
Control	male	0	5/5	5/5	5/5	5/5
Treated	male	0	9/9		9/9
		1		3/9		3/9
		2		6/9		6/9
Control	female	0	5/5	5/5	5/5	5/5
Treated	female	0	10/10		10/10
		1		4/10		5/10
		2		6/10		5/10

LF = left flank (untreated); RF = right flank (treated); erythema score: 0 = no erythema, 1 = very slight erythema, 2 = well-defined erythema, 3 = moderate to severe erythema, 4 = severe erythema to slight eschar formation

Frequence of microscopic lesions in treated group:

Microscopic lesions and grading	Left Flank (untreated)		Right Flank (treated)
	Males	Females	Males	Females
Hyperkeratosis	0/10	0/10
Grade 2			9/9	8/10
Grade 3				2/10
Acanthosis	0/10	0/10
Grade 2			9/9	9/10
Grade 3				1/10
Mononucleated Cell Infiltration	0/10	0/10
Grade 1				1/10
Grade 2			8/9	6/10
Grade 3			1/9	3/10
Vascular Ectasia	0/10	0/10
Grade 1			1/9
Grade 2			1/9	1/10

Grade 1 = slight; grade 2 = moderate; grade 3 = marked; grade 4 = severe

The key features of the study are summarised in the following table: 

No. of animals		Concentrations used			Cutaneous reactions (24 and 48 h)
Control	Treated	Intradermal	Epicutaneous	Challenge	Control	Treated
5/sex	10/sex	0.5% in paraffin oil on day 1	5% in paraffin oil on day 9-10	5% in paraffin oil on day 26	None	100%

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

Under our experimental conditions and according to the maximization method of Magnusson and Kligman, the test substance at the concentration of 5% in paraffin oil induced cutaneous reactions which were due to a sensitization process in 19/19 guinea pigs. According to the authors the allergenicity level of the test substance is very strong in the guinea pig.