Registration Dossier

Administrative data

Description of key information

Two studies skin irritation/corrosion rabbit (according to OECD 404 of 1981):
In each study, mean irritation score at 24, 48 and 72 h for each of 3 animals: 0.0 for erythema, 0.0 for oedema;
Only minor (grade 1) and fully reversible signs of irritation or no signs of irritation at any other observation time point during the study.
Two studies eye irritation, rabbit (according to OECD 405 of 1981), one dated 1992 and one dated 1996:
In the former eye irritation study, mean irritation score 24, 48 and 72 h for each of 3 animals:
0.0 for corneal opacity; 0.0 for iris lesion; 0.0 for redness of conjunctivae; 0.0 for oedema of conjunctivae (chemosis);
No ocular findings at these observation time points. Minor and fully reversible conjunctival redness (grade 1 or 2) and lacrimation (grade 1) findings at 1, 2, 4 and/or 8 h post instillation were not relevant for classification.
In the latter eye irritation study, a higher incidence and severity of conjunctival findings indicative of eye irritation in all animals and of transient corneal opacity in one animal were attributed to a major formulation constituent of the material tested in this study rather than to WS400517. This formulation constituent has been classified as skin and eye irritant category 2 [REGULATION (EC) 1272/2008].
In a Local lymph node assay stimulation indices of 1.7, 1.4 and 1.4 were attained after induction treatment with WS400517 in dimethylformamide (DMF) at 10, 25 and 50% (w/v), respectively. 50% (w/v) represented the highest suitable test concentration. Premature deaths, signs of ill health or toxicity or signs of local irritation over the treated area were not evident, although in one high dose animal dose residue was visible on the ears until its termination on Day 6.
Conclusion: No requirement of classification of WS400517 regarding skin or eye irritation/corrosion [Reg. (EC) 1272/2008].

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:
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 (incl. QA statement)
Remarks:
Certified by BAM according to DIN EN 45001.
Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
- Number: 3 animals,
- Average bodyweight: 3.0 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:
semiocclusive
Preparation of test site:
shaved
Vehicle:
other: The test material contained 50% WS400517 in organic solvent and was used after warming to 40°C
Controls:
not required
Amount / concentration applied:
500 mg test material (i.e. formulation containing 50.3% WS400517) per approx. 6 cm2 skin (2.5 cm x 2.5 cm) per animal.
The test material was warmed to 40°C for administration.
Duration of treatment / exposure:
4 hours
Observation period:
7 days post patch removal
Number of animals:
3
Details on study design:
TEST SITE PREPARATION

Samples of 500 mg of the warmed test substance were applied to the shaved skin of albino rabbits and covered with gauze squares of the size 2.5 cm x 2.5 cm on the skin. Patches were fixed with adhesive plaster. Untreated shaved skin served as controls.

TREATMENT PERIOD AND REMOVAL OF TEST SUBSTANCE

Semi-occlusive treatment lasted 4 hours. Then the dressings were removed and residual test substance was dabbed off the skin with a wet towel.

Time points of skin evaluation:

The treated skin patches were evaluated at 1 hour post patch removal and at 24, 48 and 72 h and 7 days post patch removal. Only differences from controls were considered to be positive reactions. The scoring system for the grading of skin reactions is listed in Table 1 (next field below).
Irritation parameter:
erythema score
Remarks:
as defined in Table 1
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
0
Max. score:
4
Reversibility:
fully reversible within: 24 h (erythema grade 1 was seen in 3 animals at 1 hour post patch removal)
Irritation parameter:
edema score
Remarks:
as defined in Table 1
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
0
Max. score:
4
Reversibility:
fully reversible within: 24 h (edema grade 1 was seen in 1 animal at 1 hour post patch removal)
Irritant / corrosive response data:
At 1 hour post patch removal, erythema grade 1 (slight in degree and scarcely visible) was recorded in each animal and was associated with an edema grade 1 (very slight in degree and scarcely visible) in one of them. By 24 hours post patch removal and during the remainder of the 7-day observation period signs of irritation were no longer evident.
Other effects:
Mortality or behavioural changes indicative of an adverse effect were not evident. Weighing of the animals at 7 days post treatment revealed normal body weight gain.
Interpretation of results:
GHS criteria not met
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).
Reason / purpose for cross-reference:
reference to other study
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 (incl. QA statement)
Remarks:
Certified by BAM according to DIN EN 45001.
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
- Number: 3 animals,
- Average bodyweight: 3.2 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: The test material contained 50% WS400517 in organic solvent and was used after warming to 37°C
Controls:
not required
Amount / concentration applied:
After warming undiluted test material (no vehicle) to 37°C, 0.1 ml of it was instilled 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 post instillation
Number of animals or in vitro replicates:
3 adult rabbits
Details on study design:
Eyes were evaluated for occular lesions using ultraviolet light. 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 for each animal.
Irritation parameter:
cornea opacity score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
0.2
Max. score:
4
Reversibility:
fully reversible within: 7 days post instillation
Remarks on result:
other: Only 1 animal with corneal lesions, i.e. opacity
Irritation parameter:
iris score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
0
Max. score:
2
Reversibility:
other: Iridal changes were not evident during the study
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
1.9
Max. score:
3
Reversibility:
not fully reversible within: 7 days post instillation
Remarks on result:
other: fully reversible in 2 animals, whereas in the other animal still grade 1 at 7 days post instillation
Irritation parameter:
chemosis score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
1.6
Max. score:
4
Reversibility:
fully reversible within: 6 days post instillation
Irritation parameter:
other: lacrimation score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
24/48/72 h
Score:
0.9
Max. score:
3
Reversibility:
fully reversible within: 5 days post instillation
Irritant / corrosive response data:
Adverse effects on the iris were not evident during the 7-day observation period. Corneal findings (opacity and area affected, grade 1 to 2) were confined to one animal (No. 2) and occurred rather late during the observation period (from 3 to 6 days post test material instillation). By 7 days post instillation, the corneal finding was no longer evident. Conjunctival redness, chemosis and lacrimation, grade 1 to 2, were seen in all animals and had completely resolved in two animals (Nos. 1 and 3) within 5 days after instillation. In the other animal (No. 2) a trend to reversibility was evident during the observation period with chemosis and lacrimation having completely resolved and conjunctival redness, grade 1, still present by 7 days post instillation. The ocular findings in treated eyes are detailed in Table 2.
Other effects:
Daily determination of bodyweight did not reveal any test related changes. Bodyweight gain was normal.

Table 2: Ocular Lesions of each Animal

 

 

Cornea

 

Iris

 

Conjunctivae

Animal 

Time after dosing

 

Opacity

(0-4)

Area

(0-4)

 

 

(0-2)

 

Redness

(0-3)

Chemosis

(0-4)

Lacrimation

(0-3)

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 1 hour

 

0

0

 

0

 

2

2

1

 

 2 hours

 

0

0

 

0

 

2

2

2

 

 4 hours

 

0

0

 

0

 

2

2

2

 

 8 hours

 

0

0

 

0

 

2

2

2

 

24 hours

 

0

0

 

0

 

2

2

1

 

48 hours

 

0

0

 

0

 

2

1

1

 

72 hours

 

0

0

 

0

 

1

1

0

 

96 hours

 

0

0

 

0

 

1

0

0

 

 5 days

 

0

0

 

0

 

0

0

0

 

 6 days

 

0

0

 

0

 

0

0

0

 

 7 days

 

0

0

 

0

 

0

0

0

 

 

 

 

 

 

 

 

 

 

2

 1 hour

 

0

0

 

0

 

1

1

1

 

 2 hours

 

0

0

 

0

 

2

2

2

 

 4 hours

 

0

0

 

0

 

2

2

2

 

 8 hours

 

0

0

 

0

 

2

2

2

 

24 hours

 

0

0

 

0

 

2

2

2

 

48 hours

 

0

0

 

0

 

2

2

1

 

72 hours

 

2

2

 

0

 

2

2

1

 

96 hours

 

2

2

 

0

 

2

2

1

 

 5 days

 

2

2

 

0

 

1

1

0

 

 6 days

 

1

1

 

0

 

1

0

0

 

 7 days

 

0

0

 

0

 

1

0

0

 

 

 

 

 

 

 

 

 

 

 

3

 1 hour

 

0

0

 

0

 

1

1

1

 

 2 hours

 

0

0

 

0

 

2

2

1

 

 4 hours

 

0

0

 

0

 

2

2

1

 

 8 hours

 

0

0

 

0

 

2

2

2

 

24 hours

 

0

0

 

0

 

2

2

1

 

48 hours

 

0

0

 

0

 

2

1

1

 

72 hours

 

0

0

 

0

 

2

1

0

 

96 hours

 

0

0

 

0

 

1

0

0

 

 5 days

 

0

0

 

0

 

0

0

0

 

 6 days

 

0

0

 

0

 

0

0

0

 

 7 days

 

0

0

 

0

 

0

0

0

 

 

 

 

 

 

 

 

 

 

Interpretation of results:
other: not irritating, see explanation in conclusion
Remarks:
expert judgment
Conclusions:
According to European classification rules [REGULATION (EC) 1272/2008] the degree and incidence of conjunctival redness seen in the present study could lead to classification as an eye irritant Category 2. However, the material tested in the present study contained a substantial amount of at least one formulation constituent classified as skin and eye irritant Category 2 [REGULATION (EC) 1272/2008]. Therefore and because of the absence of any relevant toxicity or indication of an irritating potential in all other toxicity studies performed with neat WS400517 or with any of its formulations, the eye irritation seen in the present study is attributed to the irritating formulation constituent and not to WS400517. Consequently, it is proposed not to classify WS400517 as an eye irritant according to EU classification rules [REGULATION (EC) 1272/2008].
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

No or only minor (grade 1) and fully reversible signs of irritation were evident in the two in vivo skin irritation studies (OECD 404), despite the presence of at least one skin and eye irritant [Category 2, REGULATION (EC) 1272/2008] formulation constituent (> 30 < 50%) in the tested WS400517 formulation. In addition, in the local lymph node assay with WS400517, signs of systemic toxicity or local irritation over the treated area were not evident, despite the presence of visible dose residue in one high dose animal until its termination on Day 6. Dermal uptake of WS400517 is likely to be low, because of its high molecular weight (897) and rather low water solubility (< 1 mg/L at 20° C). In view of this weight of evidence the data submitter proposes that 4 hours of exposure of intact, shaved rabbit skin to undiluted WS400517 would not induce any skin reactions necessitating any classification according to EU classification rules [REGULATION (EC) 1272/2008].

 

The eye irritation seen in one of the two in vivo eye irritation studies (OECD 405) was attributed to the skin and eye irritant formulation constituent rather than to WS400517, because of the absence of any relevant toxicity or signs of an irritating potential in all other toxicity studies performed with WS400517 or any of its formulations.

 

Consequently, classification of WS400517 as skin or eye irritant or corrosive is not warranted according to EU classification rules [REGULATION (EC) 1272/2008].