Registration Dossier

Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2006-12-07 to 2007-02-09
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study according to OECD guideline 404 (adopted 2002)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
Source: Harlan Italy s.r.l.
Weight: ca. 2000 g
Age: 9 – 11 weeks
Acclimatisation period: at least 10 days
Housing: individually in stainless steel cages equipped with grid floor
Diet: STANRAB (P) SQC ad libitum
Water: ad libitum

Environmental conditions:
Temperature (°C): 19 ± 2
Relative humidity (%): 55 ± 15
Photoperiod (hrs dark / hrs light): 12 / 12 by fluorescent tubes
Air changes (per hr): 15-20

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
water
Controls:
other: untreated skin sites of the same animal
Amount / concentration applied:
TEST MATERIAL
Amount applied: 0.5 g reduced to a paste with 0.1 mL sterile water
Duration of treatment / exposure:
4 h
Observation period:
up to 72 h
Number of animals:
3
Details on study design:
TEST SITE
Area of exposure: dorsolateral part of the trunk
Type of wrap: 2.5 cm x 2.5 cm square gauze fixed by a strip of synthetic film and elastic adhesive bandage

REMOVAL OF TEST SUBSTANCE
Washing with water
Time after start of exposure: 4 h

SCORING SYSTEM
According to guideline

Results and discussion

In vivo

Results
Irritation parameter:
overall irritation score
Basis:
mean
Time point:
other: 24 - 72 h
Score:
0

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute dermal irritation of L-tryptophan was investigated with rabbits in a GLP study according to OECD guideline 404. There was no indication of a systemic effect of treatment. Changes in body weight were not remarkable. No irritation was apparent following a 4 h period of exposure to the test item. Therefore, L-tryptophan can be classified as not skin irritating.