L-4-hydroxyproline

Endpoint summary

Description of key information

L-4-Hydroxyproline did not indicate a potential for dermal sensitization.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

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

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

Type of study:

other: Study with humans

Justification for non-LLNA method:

Study with humans

Species:

other: Humans

Strain:

other: Humans

Sex:

male/female

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Resulting test concentration: 50 %

Day(s)/duration:

See details of study design

Adequacy of induction:

highest technically applicable concentration used

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

0.2 g of the test material

Day(s)/duration:

24 and 48 hours

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

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

Details on study design:

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.

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 fortyeight 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.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

49

Clinical observations:

none

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.2g

No. with + reactions:

0

Total no. in group:

49

Clinical observations:

noe

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

49

Clinical observations:

none

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.2 g

No. with + reactions:

0

Total no. in group:

49

Clinical observations:

None observed

Reading:

other: no positive control was performed

Group:

positive control

Remarks on result:

other: no positive control substance was used in this human insult patch test

Interpretation of results:

GHS criteria not met

Conclusions:

The substance is not a skin sensitizer.

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

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

L-4-Hydroxyproline did not indicate a potential for dermal sensitization.