L-4-hydroxyproline

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997-03-07 to 1997-04-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Principles of method if other than guideline:

Objective: To determine by epidermal contact the primary or cumulative irritation and/or sensitization potential of the test material.
Participants:
Fifty-four (54) subjects, male and female, ranging in age from 18 to 73 years, who qualified were selected for this evaluation. Forty-nine (49) subjects completed this study. The remaining subjects discontinued their participation for various reasons, none of which were related to the use of the test material
The criteria for selection were
1. Willingness to cooperate,
2. Absence of any visible skin disease which might be confused with skin reactions from the test material,
3. Avoidance of use of topical or systemic steroids and/or antihistamines for several days prior to study initiation,
4. Dependability and intelligence in following directions, and
5. Reading, understanding, and signing an Informed Consent Form.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

L-4-hydroxyproline

EC Number:

200-091-9

EC Name:

L-4-hydroxyproline

Cas Number:

51-35-4

Molecular formula:

C5H9NO3

IUPAC Name:

L-4-hydroxyproline

Test material form:

solid: crystalline

Specific details on test material used for the study:

Lot 96003, manifactured by Kyowa Hakoo Kogyo Co., Ltd.

Test animals

Species:

other: Humans

Strain:

other: Humans

Test system

Type of coverage:

occlusive

Preparation of test site:

other: None

Vehicle:

water

Amount / concentration applied:

0.2 g of the test material was applied to the 3/4" x 3/4" gauze portion of an adhesive dressing* moistened with approximately 0.2 ml of distilled water. The
resultant test concentration was 50% aqueous. This was then applied to the appropriate treatment site to form an occluded patch.

*Manufactured by Keridall Healthcare Products, Inc. , Greenwood, SC

Duration of treatment / exposure:

The procedure described above was followed three times per week: Monday, Wednesday, and Friday for a total often applications. If a participant was unable to report for an assigned test day, one (1) makeup day was permitted. This day was added to the Induction Period. The site was marked to ensure the continuity of patch application. The participants were instructed to remove this patch after twenty-four hours, The evaluation of this site was made just prior to re-application.

Observation period:

24 h following each Tuesday and Thursday removal, and 48 h h following each Saturday removal.

Number of animals:

54 male and femal humans, of which 49 completed the study. Age ranging from 18 - 73 years.

Details on study design:

The upper back between the scapulae served as the treatment area.
If the test site exhibited a moderate (2+) reaction during the Induction Phase, application was moved to an adjacent area. Applications were discontinued
for the remainder of this test phase, ifa moderate (2+) reaction was observed on this new test site. Applications would also be discontinued if a marked
(3+) reaction was noted.
Rest periods consisted of twenty-four hours following each Tuesday and Thursday removal, and forty-eight hours following each Saturday removal
At the conclusion of a rest period of approximately two weeks following the tenth application, a challenge patch was applied to the original site and to a
virgin site. Each site was evaluated at twenty-four and forty-eight hours after application. The volar forearm served as the virgin test site.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

other: All subjects

Time point:

other: 10 d induction phase, followed by 24 h / 48 h observation.

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

other: All subjects

Time point:

other: 10 d induction phase, followed by 24 h / 48 h observation period

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The subsatnce is not irritant to the skin.

Executive summary:

The substance was applied to 54 male and female humans who had voluntered for the study. 49 subjects completed this study. The remaining subjects discontinued their participation for various reasons, none of which were related to the use of the test material.

The substance was repeatedly applied to the skin of the subjects.

Under the conditions of this study, test material L-4-Hydroxyproline, did not indicate a potential for dermal irritation and/or sensitization.