Propanoic acid, 2-hydroxy-2-methyl-, 2-propen-1-yl ester

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1998

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

Test material

Test material information

Constituent 1

Reference substance name:

prop-2-en-1-yl 2-hydroxy-2-methylpropanoate

EC Number:

700-908-3

Cas Number:

19444-21-4

Molecular formula:

C7H12O3

IUPAC Name:

prop-2-en-1-yl 2-hydroxy-2-methylpropanoate

In vivo test system

Test animals

Species:

guinea pig

Strain:

Himalayan

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL Biological Research Laboratories Ltd, 4414 Füllerinsdorf, Switzerland
- Age at study initiation: Young adult (approximately 1-3 month)
- Weight at study initiation: 309 - 439 g
- Housing: Individual
- Diet: ad libitum
- Water : ad libitum from bottles
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 50% ± 20%
- Air changes (per hr): 13-14/hour
- Photoperiod (hrs dark / hrs light): 12/12 hours

Study design: in vivo (non-LLNA)

Induction

Induction 1

Vehicle:

peanut oil

Induction 2

Concentration / amount:

Induction injection: 5.0%
Epidermal induction: 0.5%

Challenge

Challenge 1

Vehicle:

peanut oil

Challenge 2

Concentration / amount:

Induction injection: 5.0%
Epidermal induction: 0.5%

No. of animals per dose:

1

Details on study design:

RANGE FINDING TESTS:

Pre-tests, Intradermal Induction
Injections of 0.5, 1.0, 3.0, and 5.0% CA 2215 A in peanut oil produced irritation at the injection site for all concentrations. The 5.0% concentration was selected for the induction injection for the definitive test, in that it was suitable for injection, systematically well tolerated, and produced mild to moderate skin irritation. Individual irritation scores are presented in Table 1.


Pre-test, Epidermal Application
Epidermal application of 0.05, 0.1, 0.3, 0.5, 1, 5, 10, 20, 30, 50, 80 and 100% (undiluted) concentrations produced skin irritation in both animals at 1% and higher. The undiluted (100%) test article was selected for epidermal induction at the highest concentration to produce mild to moderate irritation. The 0.5% concentration was the highest concentration to produce no irritation (highest non-irritant dose), and was therefore selected for the epidermal challenge application. Individual irritation scores are presented in Table 2.


MAIN STUDY:

Day 0 – Intradermal Induction Injections
Concentration and Vehicle, test article: 5.0% in peanut oil
Pre-treatment: An area approximately 5cm x 5cm on the back of the neck was shaved approximately 1 hour before treatment.
Treatment: Three pairs of injections of 0.1ml in volume were given in the shaved area so that one of each pair was
on each side of the midline.
Vehicle control group injections: (1) adjuvant/physiological saline mixture, 1:1 v/v
(2) peanut oil
(3) peanut oil, 50% v/v with 1:1 adjuvant/physiological saline mixture
Test article group injections: (1) adjuvant/physiological saline mixture, 1:1 v/v
(2) CA 2215 A in peanut oil
(3) CA 2215 A in 1:1 adjuvant/physiological saline mixture

Day 8 – Epidermal Application Induction
Concentration and Vehicle, test article: 100 % undiluted
Treatment: A filter paper patch was fully loaded (approximately 0.4g) with undiluted test article (test article group) or peanut oil vehicle alone (vehicle control group) and held in place with the occlusive dressing for 48 hours.
Day 21- Epidermal Application Challenge
Vehicle: peanut oil
Concentration tested, test article: 0.5 % (highest non-irritant dose)
Pre-treatment: The flanks of the animals were shaved immediately prior to treatment.
Treatment: One chamber loaded with the test article/vehicle mixture (approximately 0.35 ml) was placed on one flank (test flank) and one chamber loaded with the vehicle alone was placed on the other flank
(vehicle flank) of the animals of both groups. The chambers were held in place with the occlusive
dressing for 24 hours.

Positive control substance(s):

no

Results and discussion

Any other information on results incl. tables

Pre-tests, Intradermal Induction

Injections of 0.5, 1.0, 3.0, and 5.0% CA 2215 A in peanut oil produced irritation at the injection site for all concentrations. The 5.0% concentration was selected for the induction injection for the definitive test, in that it was suitable for injection, systematically well tolerated, and produced mild to moderate skin irritation. Individual irritation scores are presented in Table 1. 

 Pre-test, Epidermal Application

Epidermal application of 0.05, 0.1, 0.3, 0.5, 1, 5, 10, 20, 30, 50, 80 and 100% (undiluted) concentrations produced skin irritation in both animals at 1% and higher. The undiluted (100%) test article was selected for epidermal induction at the highest concentration to produce mild to moderate irritation. The 0.5% concentration was the highest concentration to produce no irritation (highest non-irritant dose), and was therefore selected for the epidermal challenge application. Individual irritation scores are presented in Table 2. 

Skin Irritation Check

To document irritation by the test article during epidermal induction, sites were examined 1 hour after removal of the dressing for the epidermal induction. Positive skin irritation reactions were noted for all animals in the CA 2215 A group. There were no positive reactions among the vehicle control group animals. Results are presented in Table 3. 

Skin Reactions following Challenge Application

Positive reactions on the test flanks were only observed in one female (no.295) of the test group animals after 24 hour examination. The sensitization rate for CA 2215 A was therefore 5%. 

Sensitization reactions are summarized in table 4, and individual animal Draize scores are present in Tables 5 and 6 for vehicle control and CA 2215 A group animals, respectively. 

There was no mortality in the test. 

There were no remarkable clinical observations.

Body weights were not affected by treatment. Individual body weights are presented in Table 7. 

Table 1: Intradermal Induction Pretest, Test Article in peanut oil

Driaze Scores

SEX/ANIMAL#	AFTER 24 HOURS				AFTER 48 HOURS
	M/1	F/2	M/1	F/2	M/1	F/2	M/1	F/2
CONCENTRATION	ERYTHEMA		EDEMA		ERYTHEMA		EDEMA
0.5%	1	1	0	0	1	1	0	0
1.0%	1	1	0	0	1	1	1	1
3.0%	1	1	1	1	2	2	1	1
5.0%	1	1	1	1	2	2	2	2

 

Table 2: Epidermal Application Pretest, Test Article in peanut oil

Draize Scores

SEX/ANIMAL#	AFTER 24 HOURS				AFTER 48 HOURS
	M/1	F/2	M/1	F/2	M/1	F/2	M/1	F/2
CONCENTRATION	ERYTHEMA		EDEMA		ERYTHEMA		EDEMA
30%	1	1	0	1	1	1	0	1
50%	1	1	0	2	1	1	0	2
80%	2	2	2	2	2	2	2	2
100%	2	1	2	1	2	2	1	1

 

SEX/ANIMAL#	AFTER 24 HOURS				AFTER 48 HOURS
	M/3	F/4	M/3	F/4	M/3	F/4	M/3	F/4
CONCENTRATION	ERYTHEMA		EDEMA		ERYTHEMA		EDEMA
1%	1	1	0	0	1	1	0	0
5%	1	1	0	0	1	1	0	0
10%	1	1	1	1	1	1	1	1
20%	1	1	0	1	1	1	1	1
SEX/ANIMAL#	AFTER 24 HOURS				AFTER 48 HOURS
	M/6	F/6	M/5	F/6	M/5	F/6	M/5	F/6
CONCENTRATION	ERYTHEMA		EDEMA		ERYTHEMA		EDEMA
0.05%	0	0	0	0	0	0	0	0
0.1%	0	0	0	0	0	0	0	0
0.3%	0	0	0	0	0	0	0	0
0.5%	0	0	0	0	0	0	0	0

 

Note: Different pairs of animals (one male, one female) were used for the two pretests (Tables 1-2)

Table 3: Skin Irritation Check After Epidermal Induction

Day 10, Observations 1 hour after patch removal

VEHICLE CONTROL		TEST ARTICLE
SEX/ANIMAL#	REACTION	SEX/ANIMAL#	REACTION
M/271	-	M/276	+
M/272	-	M/277	+
M/273	-	M/278	+
+M/274	-	M/279	+
+M/275	-	M/280	+
		M/281	+
		M/282	+
		M/283	+
		M/284	+
		M/285	+
F/286	-	F/291	+
F/287	-	F/293	+
F/288	-	F/293	+
F/289	-	F/294	+
F/290	-	F/295	+
		F/296	+
		F/297	+
		F/298	+
		F/299	+
		F/300	+

-      = negative +   = positive

 

Table 4: Summary of Positive Skin Reactions after Challenge Application

Number of Animals with Positive Responses/Number of Animals in Group

	VEHICLE FLANK		TEST FANK
	24 HOURS	48 HOURS	24 HOURS	48 HOURS
CONTROL GROUP	0/10	0/10	0/10	0/10
TEST ARTICLE GROUP	0/20	0/20	1/20	0/20

 

Note : Vehicle was peanut oil for both control and CA 2215 A (intermediate of CGA 276854) groups. 

 

 

Table 5: Individual Challenge Skin Reactions, Vehicle Control Group

Driaze Scores

SEX/ANIMAL#	VEHICLE FLANK				TEST FLANK
	24 HOURS		48 HOURS		24 HOURS		48 HOURS
	ERYTHEMA	EDEMA	ERYTHEMA	EDEMA	ERYTHEMA	EDEMA	ERYTHEMA	EDEMA
M/271	0	0	0	0	0	0	0	0
M/272	0	0	0	0	0	0	0	0
M/273	0	0	0	0	0	0	0	0
M/274	0	0	0	0	0	0	0	0
M/275	0	0	0	0	0	0	0	0
F/286	0	0	0	0	0	0	0	0
F/287	0	0	0	0	0	0	0	0
F/288	0	0	0	0	0	0	0	0
F/289	0	0	0	0	0	0	0	0
F/290	0	0	0	0	0	0	0	0

 

Note: vehicle was peanut oil

 

 

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

According to the Magnusson and Klingman Maximiszation grading, CA 2215 A (Intermediate of CGA 276854) is classified as aweak sensitizer, the lowest possible grade.
According to the test results, CA 2215 A (Intermediate of CGA 276854) is not required to be classified for skin sensitization according to Commission Directive 93/21/EEC, issued May 4, 1993.

Executive summary:

A dermal sensitization test was conducted with CA 2215 A (Intermediate of CGA 276854) batch P.608005) using the Maximization procedure. Two groups of guinea pigs (10 vehicle control, 20 test) were included. On day 0 , the test group animals were given a set of intradermal injections including (including 5.0% CA 2215 A (Intermediate of CGA 276854) in peanut oil for the test group). The epidermal induction application was made on day 8; the vehicle control animals were treated with the vehicle alone, and the test animals with 100% (undiluted) CA 2215 A (Intermediate of CGA 276854). The epidermal challenge application on day 21 consisted of a paired application of the vehicle alone and 0.5% CA 2215 A (Intermediate of CGA 276854) in peanut oil in both groups. Skin reactions on both the vehicle and test flanks were scord 24 and 48 hours after completion of the challenge application, according to the Draize scale. 

Positive reactions on the test flanks were only observed in one female of the test group animals at the 24 hour examination. The sensitization rate for CA 2215 A (Intermediate of CGA 276854) was therefore 5%. There were no positive skin responses on the vehicle flanks and among the vehicle control group animals. There was no mortality, there were no remarkable clinical observations in any of the two groups. Body weights were not affected by treatment. 

According to the test results, CA 2215 A (Intermediate of CGA 276854) is not required to be classified for skin sensitization according to Commission Directive 93/21/EEC, issued May 4, 1993.