Registration Dossier

Administrative data

Endpoint:
short-term repeated dose toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 June – 28 July, 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Preliminary study performed in GLP laboratory similarly to OECD Guideline 410, used as a range-finder experiment for an OECD Guideline 414 study
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)
Deviations:
yes
Remarks:
tested at 2 dose levels only; duration of exposure: 10 days; only female animals were used; haematological tests, clinical biochemistry tests and detailed histopathological examinations were not followed
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report): Mexoryl SAB
- Physical state: Fine white powder
- Analytical purity: see confidential details
- Lot/batch No.: OpT 4E
- Date of receipt: 18 April 1995
- Storage condition of test material: At room temperature in the dark

Test animals

Species:
rat
Strain:
other: Crl:CD(SD)BR (VAF plus)
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River, UK. Ltd., Margate, England
- Weight at study initiation: 200-300 g
- Housing: Housed individually in grid-bottomed polypropylene cages
- Diet (e.g. ad libitum): Pelleted diet SQC Rat and Mouse No. 1 (expanded) (Special Diets Services Limited, Witham, Essex, U.K.), ad libitum
- Water (e.g. ad libitum): Tap water (in bottles), drawn directly from the water mains, ad libitum
- Acclimation period: 18 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21-25 °C
- Humidity: 40-69 %
- Air changes: 16 air changes/h
- Photoperiod: 12 h dark/ 12 h fluorescent light

Administration / exposure

Type of coverage:
open
Vehicle:
other: PEG 300
Details on exposure:
TEST SITE
- Area of exposure: Clipped area of the back
- % coverage: Not less than 10 % of the body area
- Type of wrap if used: Test article formulations were applied directly to the skin of the clipped area of the back.
- Time intervals for shavings or clipplings: Approximately 24 h before the start of dosing, fur (equivalent to not less than 10 % of the surface area of the body) was removed from the dorsal area by clipping or shaving. During the dosing period, the application sites were clipped as often as was necessary to maintain them free of fur.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Test sites were washed using warm water to remove residual test article and the skin was then blotted dry with a paper towel.
- Time after start of exposure: Approximately 6 h

TEST MATERIAL
- Constant volume or concentration used: Yes, 2 mL/kg bw

USE OF RESTRAINERS FOR PREVENTING INGESTION: Yes, animals were fitted with Elizabethan collars for the 6 h exposure period in order to prevent ingestion of the test article.
Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
Not applicable
Duration of treatment / exposure:
6 h/day; 10 days
Frequency of treatment:
Once daily
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 2 and 5 %
Basis:
other: directly applied on skin
No. of animals per sex per dose:
Five virgin females/dose
Control animals:
yes, concurrent vehicle
Details on study design:
- Rationale for animal assignment: Selected females were allocated randomly to treatment group using a stratified bodyweight procedure.
Positive control:
No

Examinations

Observations and examinations performed and frequency:
MORTALITIES:
- Time schedule: Twice daily

CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: Daily

BODY WEIGHT: Yes
- Time schedule for examinations: Recorded over Days 1-4, 4-7 and 7-10 of the study

FOOD CONSUMPTION: Yes
- Time schedule for examinations: Daily
Sacrifice and pathology:
GROSS PATHOLOGY: Yes, all surviving animals were killed by CO2 asphyxiation at the end of treatment period and were submitted to the procedure of necropsy including the following examinations: appearance of tissues in situ from the cranial, thoracic and abdominal cavities.
HISTOPATHOLOGY: Treated skin and a section of control skin (taken from the right hind limb) from all animals was fixed and stored in neutral buffered formaldehyde. These tissues were not examined microscopically.
Other examinations:
None
Statistics:
Analysis of variance (ANOVA) was performed on all parameters, using treatment group as the factor in the analysis. Residuals from this preliminary analysis were examined for heterogeneity of variance using Levenes test. If Levenes test was significant at the 1 % level, then the particular variable concerned was subjected to a non-parametric analysis. Otherwise, William’s test was performed to compare the high dose with control at the two-sided 5 % level. If this test was statistically significant then comparisons of the subsequent doses against control was performed at the one-sided 5 % level until a non-significant difference was found, at which point the testing stopped. The highest dose at which the difference from control was non-significant was deemed to be the no-effect level.
If Levenes test indicated that there were significant differences in the treatment group variances or if a parametric analysis was deemed to be inappropriate, then a Kruskal-Wallis ANOVA was performed to assess overall differences between the treatment groups, followed by Shirley's nonparametric version of William’s test, which is based on mean ranks rather than the arithmetic means.

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Dermal irritation:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY:
- No premature death was noted.
- Animals from the group treated at 5 % were observed to be scratching at the application site from Day 8 of the dosing period onwards.
- No other treatment-related clinical observation was noted.

DERMAL IRRITATION:
- Between 2 and 5 animals from the group treated at 5 % were observed with very slight erythema from Day 6 onwards and one female was observed with well-defined erythema between Days 8 and 10 of the dosing period. In addition, between 3 and 4 animals from this group were observed with very slight oedema from Day 7 of the dosing period. There were no skin reactions in either of the other groups.

BODY WEIGHT AND WEIGHT GAIN:
- No effect of treatment was noted on bodyweight gain throughout the dosing period.
- Occasionally, transient weight losses were observed which, because of the small group sizes, skewed the means.

FOOD CONSUMPTION:
- No effect of treatment was noted on mean food consumption.

GROSS PATHOLOGY
- All animals from the group treated at 5 % were observed with scabbing (minimal/moderate) at the application site at necropsy.
- No other treatment-related findings were observed at necropsy.

- For more details, refer attached PDF document titled 'Figures and tables'

Effect levels

open allclose all
Dose descriptor:
NOEL
Remarks:
local effect
Effect level:
2 other: %
Based on:
test mat.
Sex:
female
Basis for effect level:
other: At 5 %, minimal irritation characterised by slight to well-defined erythema and oedema were noted from Day 6 onwards. At necropsy, scabbing (minimal/moderate) was noted in all animals treated with 5 %. No effects were observed at 2 %.
Dose descriptor:
NOEL
Remarks:
systemic effect
Effect level:
> 5 other: %
Based on:
test mat.
Sex:
female
Basis for effect level:
other: no treatment related-effects were observed on mortality, clinical signs, bodyweight gain and food consumption

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:
Under the test conditions, the No Observed Effect Levels (NOEL) for local and systemic effects for Mexoryl SAB to female rats were considered to be 2 and > 5 %, respectively.
Executive summary:

In a repeated dose dermal toxicity study conducted similarly to the OECD Guideline 410 and in compliance with GLP, groups of five virgin female rats of the Crl:CD (SD) BR (VAF plus) strain were dosed once daily for 10 days by dermal application with suspensions of Mexoryl SAB at dose levels of 2 and 5 %, using a dose volume of 2 mL/kg bw. A similar group of females was dosed with the vehicle (PEG 300) only, and served as controls. The formulations were applied directly to the skin of a clipped area of the back (not less than 10 % of the body area) and, approximately 6 h after application, the test site was washed using warm water and dried. Examinations during the study included: mortality, clinical observation, body weight change, evaluation of cutaneous tolerance and macroscopic necropsy.

No mortality was recorded during the study. Animals treated at 5 % were observed to be scratching at the application site from Day 8 of the dosing period onwards. In this group, very slight erythema was noted in 2-5 animals from Day 6 onwards and well-defined erythema was noted in one female between Days 8 and 10 of the dosing period. In addition, between 3 and 4 animals from this group were observed with very slight oedema from Day 7 of the dosing period. No treatment-related changes were observed in food consumption and bodyweight gain. Occasionally, transient weight losses were observed which, because of the small group sizes, skewed the means. All animals from the group treated at 5 % were observed with scabbing (minimal/moderate) at the application site at necropsy. No other treatment-related findings were observed at necropsy.

Under the test conditions, the No Observed Effect Levels (NOEL) for local and systemic effects for Mexoryl SAB to female rats were considered to be 2 and > 5 %, respectively.