Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
The study was conducted between 29 October 2015 and 19 November 2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report date:
2016

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: Japanese MAFF, 2000
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Test material form:
solid: particulate/powder

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
Animals and Animal Husbandry
Five male and five female Wistar (RccHan™:WIST) strain rats were supplied by Envigo RMS (UK) Limited, Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non pregnant. After an acclimatization period of at least 5 days the animals were selected at random and given a number unique within the study by indelible ink marking on the tail and a number written on a cage card. At the start of the study the animals weighed at least 200 g, and were 8 to 12 weeks of age. The weight variation did not exceed ±20% of the mean weight for each sex.

The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The initial two animals were housed individually throughout the study. The further group of eight animals (four male and four female) were housed individually during the 24 Hour exposure period and in groups of four, by sex, for the remainder of the study. Free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Envigo RMS (UK) Limited, Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analyzed and were considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.


Justification
Rats are the preferred species of choice as historically used for safety evaluation studies and are specified in the appropriate test guidelines.

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
water
Details on dermal exposure:
Test Item Formulation and Experimental Preparation
For the purpose of the study the test item was weighed out according to each animal’s individual body weight and moistened with distilled water prior to application.
The absorption of the test item was not determined.

Procedure
On the day before treatment the back and flanks of each animal were clipped free of hair.

In the absence of data suggesting the test item was toxic, one male and one female rat were initially treated with the test item at a dose level of 2000 mg/kg.

The appropriate amount of test item, moistened with distilled water, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area). A piece of surgical gauze was placed over the treatment area and semi occluded with a piece of self adhesive bandage. Shortly after dosing the dressings were examined to ensure that they were securely in place.
After the 24 Hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test item.

As no mortalities were noted a further group of animals (four males and four females) was similarly treated with the test item at a dose level of 2000 mg/kg body weight to give a total of five males and five females. The animals were caged individually for the 24 Hour exposure period. After the 24 Hour contact period the bandages were carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test item. These animals were returned to group housing for the remainder of the test period.
Duration of exposure:
24 hours
Doses:
2000 mg/kg
No. of animals per sex per dose:
Five males and five females
Control animals:
no
Details on study design:
The animals were observed for deaths or overt signs of toxicity 30 minutes, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days.

After removal of the dressings and subsequently once daily for 14 days, the test sites were examined for evidence of primary irritation. Any other skin reactions, if present were also recorded.
Individual body weights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.
At the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Evaluation of Data
Data evaluations included the relationship, if any, between the exposure of the animal to the test item and the incidence and severity of all abnormalities including behavioral and clinical observations, gross lesions, body weight changes, mortality and any other toxicological effects.
Using the mortality data obtained, an estimate of the acute dermal median lethal dose (LD50) of the test item was made.
Statistics:
No data

Results and discussion

Preliminary study:
No data
Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
There were no deaths.
Clinical signs:
No signs of systemic toxicity were noted during the observation period.
Body weight:
Two females showed no gain in body weight during the first week with expected gain in body weight during the second week. One other female showed expected gain in body weight during the first week but body weight loss during the second week. The remaining seven animals showed expected gains in body weight over the study period.
Gross pathology:
No abnormalities were noted at necropsy.
Other findings:
Dermal Reactions
Dark orange colored staining, which prevented evaluation of erythema, was noted 1 day after dosing at the test sites of the two initial treated animals. Pale orange/yellow colored staining, not preventing evaluation of skin responses, was noted at the test sites the initial two treated animals 2 days after dosing and up to 11 Days after dosing.

Very slight to well-defined erythema and very slight edema were noted at the test site of the initial treated male with very slight erythema and very slight edema noted at the test site of initial treated female.

Pale orange/yellow colored staining, not preventing evaluation of skin responses, was noted at the test sites of the four additional treated males and four additional treated females during the study.

Very slight erythema, with or without very slight edema, was noted at the test sites of the four additional treated females up to 6 Days after dosing. There were no signs of dermal irritation noted at the test sites of the four additional treated males.

Any other information on results incl. tables

Individual Clinical Observations and Mortality Data

Dose Level mg/kg

Animal Number and Sex

Effects Noted After Dosing
(Hours)

Effects Noted During Period After Dosing
(Days)

½

1

2

4

1

2

3

4

5

6

7

8

9

10

11

12

13

14

2000

1-0

Male

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-0

Male

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-1

Male

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-2

Male

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-3

Male

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

2-0

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

4-0

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

4-1

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

4-2

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

4-3

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 = No mortality or signs of systemic toxicity

Individual Dermal Reactions - Males

Dose Level mg/kg

Animal Number and Sex

Observation

Effects Noted After Initiation of Exposure (Days)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

2000

1-0

Male

Erythema

?s

2

1

1

1

1

1

0

0

0

0

0

0

0

Edema

1

1

1

1

1

1

1

0

0

0

0

0

0

0

Other

0

STA

STA

STA

STA

STA

STA

STA

STA

STA

0

0

0

0

3-0

Male

Erythema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Edema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Other

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-1

Male

Erythema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Edema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Other

STA

STA

STA

STA

0

0

0

0

0

0

0

0

0

0

3-2

Male

Erythema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Edema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Other

STA

STA

STA

STA

STA

0

0

0

0

0

0

0

0

0

3-3

Male

Erythema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Edema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Other

STA

STA

STA

STA

STA

0

0

0

0

0

0

0

0

0

0= No reactions                   

?s = Dark orange colored staining preventing evaluation of erythema                   

STA = Pale orange/yellow colored staining

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg body weight.
Executive summary:

Introduction

The study was performed to assess the acute dermal toxicity of the test item in the Wistar strain rat.

 

Methods

Initially, two animals (one male and one female) were given a single, 24 hour, semi‑occluded dermal application of the test item to intact skin at a dose level of 2000 mg/kg body weight. Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

 

Results

Mortality. There were no deaths.

Clinical Observations. There were no signs of systemic toxicity.

Dermal Irritation. Very slight to well‑defined erythema and very slight edema were noted at the test sites of one male and all females. There were no signs of dermal irritation noted at the test sites of four males.

Body Weight. Two females showed no gain in body weight during the first week with expected gain in body weight during the second week. One other female showed expected gain in body weight during the first week but body weight loss during the second week. The remaining seven animals showed expected gains in body weight over the study period.

Necropsy. No abnormalities were noted at necropsy.

 

Conclusion

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg body weight.