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Description of key information

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records
Reference
Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study was conducted according to internationally accepted technical guidelines and in compliance with GLP in a contract research organization. The study is scientifically valid and the report is fully adequate for assessment, despite some minor restrictions (e.g. due to limited reporting).
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
of 1981
Deviations:
yes
Remarks:
24 h instead of 4 h exposure to a 50% emulsion of test substance in vehicle. Skin examination 0 h, 48 h and 6 days after patch removal.
Qualifier:
according to guideline
Guideline:
other: Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics, Division of Pharmacology, FDA
Deviations:
not specified
GLP compliance:
yes
Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
- Number: 5 animals,
- Average bodyweight: 3 kg
- Housing: Individual housing in cages.
- Diet: Commercially available standard laboratory diet for rabbits ( Altromin, Lage, Germany).
- Water: Ad libitum

ENVIRONMENTAL CONDITIONS

Room temperature kept constant at 18±2°C, the relative humidity at 50-60%. 12 hours illumination per day.

Type of coverage:
occlusive
Preparation of test site:
other: abraded versus only shaved
Vehicle:
other: Mixture of CMC (carboxymethyl cellulose) and Tween 20 containing 50% test substance
Controls:
not required
Amount / concentration applied:
Dose formulation: Emulsion in mixture of CMC (carboxymethyl cellulose) and Tween 20 containing 50% of the test substance

0.5 g of a 50% test substance emulsion (after warming it up to 37°C) was administered to the skin by means of a "2.5 cm2" cellulose patch.*

* Comment by the data submitter:
There is no indication in the report, whether the size of treated skin patches was inadvertently stated as only "2.5 cm2" in reality having been sized 2.5 cm x 2.5 cm (i.e. ca. 6 cm2) or whether, contrarily to the cited OECD 404 test guideline, the size of the treated skin patches was really confined to only 2.5 cm2. Regardless whether the treated skin patch was ca. 6 cm2 or only 2.5 cm2, the study results are considered to be valid for assessment.
Duration of treatment / exposure:
24 hours
Observation period:
7 days (i.e. the final observation time point was 6 days post patch removal)
Number of animals:
5
Details on study design:
TEST SITE PREPARATION

Samples of 0.5 g of the test emulsion (containing 50% test substance) were applied to the shaved intact and to shaved and then abraded skin of albino rabbits by means of cellulose patches. Patches were fixed with Leukoplast(R) and the whole trunk of each animal was enwrapped by a rubber cloth during the 24 hour treatment period, in order to delay evaporation of substances. From the coverage of the whole animal trunk (patches inclusive) with rubber cloth occlusive treatment was concluded by the data submitter, although the report did not specify whether this coverage was considered to be occlusive or semi-occlusive.

Two untreated skin sites (one of shaved intact skin and one of shaved and then abraded skin) served as controls. Only skin reactions different to controls were graded as positive skin reactions.


TREATMENT PERIOD AND REMOVAL OF TEST SUBSTANCE

Occlusive treatment lasted 24 hours. Then the dressings were removed. There was no mentioning in the report that exposed skin patches were cleaned from residual test substance after treatment.

TIME POINTS OF SKIN EVALUATION:

The treated skin patches were evaluated 24 and 72 hours and 7 days post application (i.e. immediately and 48 hours and 6 days post patch removal). The scoring system for the grading of skin reactions is listed in Table 1 (next field below).

Reporting of irritation results in the present robust study summary has been focused to those attained on intact skin, as currently valid test guidelines do not require treatment of abraded skin.
Irritation parameter:
erythema score
Remarks:
as defined in Table 1
Basis:
mean
Remarks:
over 5 animals and 2 time points
Time point:
other: 24 and 72 h post treatment start
Score:
0
Max. score:
4
Reversibility:
other: erythema formation was not evident
Remarks on result:
other: 50% test substance emulsion administered to intact skin for 24 hours
Irritation parameter:
edema score
Remarks:
as defined in Table 1
Basis:
mean
Remarks:
over 5 animals and 2 time points
Time point:
other: 24 and 72 h post treatment start
Score:
0
Max. score:
4
Reversibility:
other: edema formation was not evident
Remarks on result:
other: 50% test substance emulsion administered to intact skin for 24 hours
Irritation parameter:
erythema score
Remarks:
as defined in Table 1
Basis:
mean
Remarks:
over 5 animals and 2 time points
Time point:
other: 24 and 72 h post treatment start
Score:
0.4
Max. score:
4
Reversibility:
fully reversible within: 72 hours post treatment start, i.e. within 48 hours post patch removal
Remarks on result:
other: 50% test substance emulsion administered to abraded skin for 24 hours
Irritation parameter:
edema score
Remarks:
as defined in Table 1
Basis:
mean
Remarks:
over 5 animals and 2 time points
Time point:
other: 24 and 72 h post treatment start
Score:
0
Max. score:
4
Reversibility:
other: edema formation was not evident
Remarks on result:
other: 50% test substance emulsion administered to abraded skin for 24 hours
Irritant / corrosive response data:
In each animal, shaved intact skin patches treated with a 50% test substance emulsion were free from erythema, scab or edema formation at any observation time point of the study.

On abraded skin patches treated with a 50% test substance emulsion, the only findings were erythema grade 1 at 24 hours post treatment start in 4 of 5 animals which had reversed to normal by 72 hours post treatment start in all affected animals. The fifth animal was free from skin reactions at all observation time points and the 4 affected animals at 72 hours and 7 days post treatment start. Edema were not evident.
Other effects:
None
Interpretation of results:
other: not irritating according to EU regulation
Conclusions:
Occlusive administration of a 50% test substance emulsion (i.e. containing 50% WS400130) to shaved, intact skin of five rabbits for 24 hours did not induce any skin reactions during the present study. The same treatment to abraded skin induced only grade 1 erythema in 4 of 5 animals which were fully reversible within 72 hours post treatment start. In view of the absence of any irritating effects of the 50% emulsion on intact skin and the very mild and fully reversible erythema reaction of abraded skin during the present study, the submitter proposes that only 4 h exposure of intact skin to undiluted WS400130 would not induce skin reactions necessitating any labelling regarding skin irritation according to EU classification rules [REGULATION (EC) 1272/2008].
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study was conducted according to internationally accepted technical guidelines and in compliance with GLP in a contract research organization. The study is scientifically valid and the report is fully adequate for assessment, despite some minor restrictions (e.g. due to limited reporting).
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Version / remarks:
of 1981
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics, Division of Pharmacology, FDA
Deviations:
not specified
GLP compliance:
yes
Species:
rabbit
Strain:
other: Tattooed New Zealands (albino rabbit)
Details on test animals or tissues and environmental conditions:
- Number: 6 animals,
- Bodyweight: 2.5 to 3.0 kg
- Housing: Individual housing in cages.
- Diet: Commercially available standard laboratory diet for rabbits ( Altromin, Lage, Germany).
Prior to dosing the animals were starved for 16 hours.
- Water: Ad libitum

ENVIRONMENTAL CONDITIONS

Room temperature kept constant at 18±2°C, the relative humidity at 50-60%. 12 hours illumination per day.
Vehicle:
other: CMC (carboxymethyl cellulose "Tylose") containing 40% test substance
Controls:
not required
Amount / concentration applied:
Undiluted test substance could not be administered. Therefore, a dose formulation was prepared containing 40.5% WS400130.
After warming this test substance dilution to 40°C, 0.1 ml of it was administered into the conjunctival sac of one eye per rabbit. The contralateral eye remained untreated to serve as a control.
Duration of treatment / exposure:
There was no mentioning in the report that eyes were rinsed after treatment. Consequently the treatment/exposure period was equivalent to the entire observation period following administration, which was 7 days, or lasted until removal of the test material by physiological mechanisms, whichever happened sooner.
Observation period (in vivo):
7 days (i.e. the final observation time point was 7 days post instillation)
Number of animals or in vitro replicates:
6 adult rabbits
Details on study design:
Eyes were evaluated for occular lesions using ultraviolet light. Before and after the test the eyes of all animals were examained after staining with 2% fluorescein thus supporting the recognition of corneal lesions.

The numerical scoring system listed in Table 1 in the field below was adopted. Time points of evaluation were: Pretest (prior to treatment), 1, 2, 4, 8, 24, 48, 72 and 96 hours after administration and daily thereafter until 7 days after administration. Grades attained at 24, 48 and 72 hours after administration were included in the mean gradings of ocular lesions used for eye irritation/corrosion classification.
Irritation parameter:
cornea opacity score
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
4
Reversibility:
other: Corneal irritation or opacity was not evident during the study
Remarks on result:
other: Treated with a dose formulation containing 40.5% WS400130
Irritation parameter:
iris score
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
2
Reversibility:
other: Iridal changes were not evident during the study
Remarks on result:
other: Treated with a dose formulation containing 40.5% WS400130
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
3
Reversibility:
fully reversible within: 4 hours
Remarks on result:
other: Treated with a dose formulation containing 40.5% WS400130
Irritation parameter:
chemosis score
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
4
Reversibility:
other: Chemosis was not evident during the study
Remarks on result:
other: Treated with a dose formulation containing 40.5% WS400130
Irritation parameter:
other: lacrimation score
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
3
Reversibility:
fully reversible within: 4 hours
Remarks on result:
other: Treated with a dose formulation containing 40.5% WS400130
Irritant / corrosive response data:
Corneal and iridic lesions and chemosis were not evident throughout the study. Conjunctival redness and lacrimation, both findings grade 1, were seen in all treated eyes at 1 and 2 hours post instillation having completely disappeared in all animals by 4 hours post instillation. Examination of the eyes at 4 and 8 hours post instillation and daily afterwards until 7 days post instillation did not reveal any findings.
Other effects:
There was no mentioning of any other effects in the report.
Interpretation of results:
other: not irritating according to EU regulation
Conclusions:
WS400130 could not be administered undiluted. Therefore, a dilution in CMC (Tylose) containing 40.5% WS400130 was tested. The outcome of the present study does not necessitate any labelling regarding eye irritation according to EU classification rules [REGULATION (EC) 1272/2008]. The findings noted were very minor in degree, restricted to the 1 and 2 hour post instillation time points and fully reversible within 4 hours. Therefore, they fell within the category “not irritating to eyes”.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Justification for classification or non-classification

There were no irritating effects on intact skin treated for 24 hours with an emulsion containing 50% WS400130 and only mild and fully reversible erythema reactions in abraded skin after such treatment. Therefore, the submitter proposes that only 4 hours of exposure of intact skin to undiluted WS400130 would not induce any skin reactions necessitating any classification regarding skin irritation or corrosion according to EU classification rules [REGULATION (EC) 1272/2008].

 

Instillation of undiluted WS400130 to the conjunctival sac was not possible. Therefore, eye irritation was tested in vivo using a dilution in CMC (Tylose) containing 40.5% WS400130. Findings noted (conjunctival reddening and lacrimation) were very minor in degree and fully reversible within 4 hours post instillation not necessitating any classification regarding eye irritation/corrosion according to EU classification rules.