[No public or meaningful name is available]

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 27 April to 10 October 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, GLP compliant; no restrictions, fully adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Limited, Margate, Kent
- Age at study initiation: Five to eight weeks
- Weight at study initiation: 138 to 178 g (males), 132 to 172 g (females)
- Fasting period before study: None
- Housing: In groups of up to four by sex in polypropylene grid-floor cages suspended over trays lined with absorbant paper
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: At least seven days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±2
- Humidity (%): 55±15
- Air changes (per hr): At least 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: A known amount of test material was mixed with a small amount of basal laboratory diet for nineteen minutes at a constant speed, setting 1 in a Hobart QE200 mixer. This pre-mix was then added to a larger amount of basal laboratory diet and mixed for a further thirty minutes at a constant speed, setting 1 in a Hobart H800 mixer.


DIET PREPARATION
- Rate of preparation of diet (frequency): Prior to treatment and then at regular intervals during the three month study period.
- Mixing appropriate amounts with (Type of food): Rat and Mouse SQC Ground Diet No. 1 Diet, Special Diets Services
Limited, Witham, Essex, UK
- Storage temperature of food: The diet was stored at room temperature in labelled, double black plastic bags in labelled, covered plastic bins when not in use.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The standard and sample solutions were analysed by HPLC using the following conditions:
HPLC : Agilent Technologies 1050, incorporating autosampler
and workstation
Column : Microsorb-MV-100-5 C18 (150 x 4.6 mm id)
Mobile phase : acetonitrile:0.1% orthophosphoric acid (85:15 v/v)
Flow-rate : 1 ml/min
UV detector wavelength : 215 nm
Injection volume : 10 μl
Retention time : ~ 3.3 mins

Duration of treatment / exposure:

Ninety days

Frequency of treatment:

Daily, seven days per week

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0, 250, 5000 and 20000 ppm
Basis:
nominal in diet

Doses / concentrations 2

Remarks:

Doses / Concentrations:
0, 21, 424 and 1682 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

Twenty

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: Based on previous toxicity work
- Rationale for animal assignment: Not applicable
- Rationale for selecting satellite groups: Not applicable
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale: Not applicable

Positive control:

None

Examinations

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once daily


BODY WEIGHT: Yes
- Individual bodyweights were recorded on Day 1 (prior the start of treatment) and at weekly
intervals thereafter. Bodyweights were also recorded at terminal kill.


FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption was recorded for each cage group at weekly intervals throughout the study.



WATER CONSUMPTION: Yes
- Time schedule for examinations: Water intake was observed daily, for each cage group, by visual inspection of the water bottles for any overt changes.


OPHTHALMOSCOPIC EXAMINATION: Yes / No / No data
- The eyes of ten selected male and female animals from the control, low, intermediate and high dose animals were examined pre-treatment and before the end of the treatment period (during Week 12).


HAEMATOLOGY: Yes
- Time schedule for collection of blood: Week 3, Week 7, and at the end of the study (Day 90).
- Anaesthetic used for blood collection: No
- Animals fasted: No
- How many animals: Ten male and ten female animals from each test and control group.
- Parameters checked in table [No.15] were examined.


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Week 3, Week 7, and at the end of the study (Day 90).
- Animals fasted: No
- How many animals: Ten male and ten female animals from each test and control group.
- Parameters checked in table [No.16] were examined.


URINALYSIS: Yes
- Time schedule for collection of urine: Final week of treatment.
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked in table [No.17] were examined.


NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: Week 12 (functional performance), prior to exposure and weekly during treatment (functional/behaverioural toxicity)
- Dose groups that were examined: All
- Battery of functions tested: sensory reactivity, grip strength, motor activity

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see table 18)
HISTOPATHOLOGY: Yes (see table 19)

Other examinations:

None

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

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):

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

HISTOPATHOLOGY:
KIDNEY: A lower incidence of globular accumulations of eosinophilic material in the proximal tubular epithelium was encountered as a probable consequence of treatment in males at 1682 mg/kg bw/day.
SPLEEN: A greater incidence of higher grades of extramedullary haemopoiesis was observed in relation to treatment for females treated with 1682 mg/kg bw/day.
BONE MARROW: Generally lower grades of severity of adipose infiltration of the marrow were seen among females treated with 1682 mg/kg bw/day.
These changes, in the absence of any degenerative changes and associated haematological changes, are generally reversible and as such, are not considered as adverse. The absence of any haematological changes also minimises the toxicological significance of these findings.

These changes were considered not to represent an adverse health effect and as such, the ‘No Observed Adverse Effect Level’ (NOAEL) was considered as 1682 mg/kg bw/day.

Effect levels

Dose descriptor:

NOAEL

Effect level:

1 682 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: no adverse health effects

Target system / organ toxicity

Critical effects observed:

not specified