Registration Dossier

Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
October 8, 2007 - November 20, 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Corsair Clear #34
- Substance type: Clear white lumpy solid
- Physical state: Solid
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: Approximately 6 weeks.
- Weight at study initiation: males 163-174 grams; females 129-144 grams
- Fasting period before study: not applicable
- Housing: Group housing of 5 animals per sex in Macrolon cages (MIV type) with sterilised sawdust as bedding material
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period:At least 5 days before the start of treatment under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.3 – 22.7C
- Humidity (%): 25 - 92%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
propylene glycol
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulations (w/w) were prepared daily within 4 hours prior to dosing, and were homogenised to visually acceptable levels. Adjustment was made for specific gravity of the test substance and vehicle. No correction was made for the purity of the test substance.

VEHICLE
- Justification for use and choice of vehicle (if other than water): Based on trial formulations performed at NOTOX and on information from the sponsor.
- Concentration in vehicle: 0, 10, 30, 200 mg/ml
- Amount of vehicle (if gavage): 5 ml/kg
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples of formulations were analysed on a single occasion to check homogeneity (highest and lowest concentration) and accuracy of preparation (all concentrations). Stability in vehicle over 5 hours was also determined (highest and lowest concentration). The analytical method used was HPLC-UV (see section 8).
Test substance formulations in propylene glycol were noted as stable for at least 5 hours and formed a homogeneous suspension at the concentrations tested. Analysis of the accuracy of dose preparations revealed mean values within the range of 98-107% of nominal, which was considered to represent an acceptable level of accuracy for formulations of this type.
Duration of treatment / exposure:
At least 28 days.
Frequency of treatment:
Once daily, 7 days per week, approximately the same time each day with a maximum of 4 hours difference between the earliest and latest dose.
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
1000 mg/kg bw/d
Basis:
actual ingested
Remarks:
Doses / Concentrations:
150 mg/kg bw/d
Basis:
actual ingested
Remarks:
Doses / Concentrations:
50 mg/kg bw/d
Basis:
actual ingested
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Dose levels are based on results of a 5-day dose range finding study with CORSAIR CLEAR #34

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: At least twice daily
- Cage side observations: Mortality / viability

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: At least once daily

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION: Weekly
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: immediately prior to scheduled post mortem examination at the end of the treatment
- Anaesthetic used for blood collection: Yes (iso-flurane)
- Animals fasted: Yes, overnight
- How many animals: all animals
- Parameters examined: White blood cells, Differential leucocyte count (neutrophils, lymphocytes, monocytes,eosinophils, basophils), Red blood cells, Reticulocytes, Red blood cell distribution width, Haemoglobin, Haematocrit, Mean corpuscular volume, Mean corpuscular haemoglobin, Mean corpuscular haemoglobin concentration, Platelets, Prothrombin time, Activated Partial thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: immediately prior to scheduled post mortem examination at the end of the treatment
- Animals fasted: Yes, overnight
- How many animals: all animals
- Parameters examined: Alanine aminotransferase, Aspartate aminotransferase, Alkaline phosphatase, Total Protein, Albumin, Total Bilirubin, Urea, Creatinine, Glucose, Cholesterol, Sodium, Potassium, Chloride, Calcium, Inorganic Phosphate

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: During week 4 of treatment
- Dose groups that were examined: all dose groups
- Battery of functions tested: hearing ability, pupillary reflex, static righting reflex and grip strength, motor activity test
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
Adrenal glands, Aorta, Brain [cerebellum, mid-brain, cortex], Caecum, Cervix, (Clitoral gland), Colon, Duodenum, Epididymides, (Eyes with optic nerve [if detectable] and Harderian gland), (Female mammary gland area), (Femur including joint), Heart, Ileum, Jejunum, Kidneys, (Larynx), (Lacrimal gland, exorbital), Liver, Lung, infused with formalin, Lymph nodes - mandibular, mesenteric, (Nasopharynx), Oesophagus, Ovaries, Pancreas, Peyer's patches [jejunum, ileum] if detectable, Pituitary gland, (Preputial gland), Prostate gland, Rectum, (Salivary glands - mandibular, sublingual) ,Sciatic nerve,
Seminal vesicles, (Skeletal muscle), (Skin) , Spinal cord -cervical, midthoracic, lumbar, Spleen, Sternum with bone marrow, Stomach, Testes, Thymus,
Thyroid including parathyroid [if detectable], (Tongue), Trachea, Urinary bladder, Uterus, Vagina, All gross lesions

Tissues/organs mentioned in parentheses were not examined by the pathologist since there were no changes in macroscopic appearance that were indicative of (potential) toxicity.

The following organ weights and terminal body weight were recorded from the surviving animals on the scheduled day of necropsy:
Adrenal glands, Brain, Epididymides, Heart, Kidneys, Liver, Spleen, Testes, Thymus

HISTOPATHOLOGY: Yes
The following slides were examined by a pathologist:
- all tissues collected at the scheduled sacrifice from all group 1 and 4 animals,
- all gross lesions.
Based on (possible) treatment-related changes in adrenal glands, epididymides and thyroid, the histological examination was extended to those particular organs of all males of groups 2 and 3.
Tissues/organs mentioned in parentheses mentioned above under GROSS PATHOLOGY were not examined by the pathologist, since no signs of toxicity were noted at macroscopic examination.
Statistics:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test1 (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test2 (many-to-one rank test) was applied when the data could not be assumed to follow a normal distribution.
- The exact Fisher-test3 was applied to frequency data.
All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance.

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):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
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:
HAEMATOLOGY
The statistically significant higher platelet counts of females at 1000 mg/kg/day were considered to be of no toxicological significance as control values were considered to be slightly high, and the mean at 1000 mg/kg/day was within the normal range.

CLINICAL CHEMISTRY
The statistically significant higher albumin levels of males at 150 mg/kg/day occurred in the absence of a dose-related trend, and the mean was within the range considered normal for rats of this age and strain. No toxicological significance was therefore ascribed to this change.

GROSS PATHOLOGY
Two males each at 150 and 1000 mg/kg/day, and one control male and one male at 50 mg/kg/day showed a yellowish or greenish soft nodule on the left or right epididymides. Based on histopathological assessment, this was considered not to be related to treatment with the test substance.

HISTOPATHOLOGY: NON-NEOPLASTIC
Adrenal cortical hypertrophy was recorded in 4/5 males at 1000 mg/kg/day (minimal or mild degree). Thyroid follicular hypertrophy was noted in 3/5 males at 1000 mg/kg/day (minimal or mild degree), and 2/5 males at 150 mg/kg/day (minimal degree).
Sperm granuloma/spermatocoele were noted in 1/5 males at 50 and 1000 mg/kg/day, and in 2/5 males at 150 mg/kg/day. A mild oedema of the epididymides was observed in one control male and one male at 1000 mg/kg/day The incidence of these findings was higher than normally encountered in this type of study. However, in the absence of a dose-related distribution and the isolated nature of these findings, these were considered changes unrelated to treatment with the test substance.
All other microscopic findings were within the range of background pathology encountered in Wistar rats of this age and strain and occurred at similar incidences and severity in both control and treated rats.

Effect levels

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: see 'Remark'

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Wistar rats were treated with CORSAIR CLEAR #34 for 28 consecutive days by daily oral gavage at dose levels up to 1000 mg/kg/day.
Treatment-related changes were confined to hypertrophy of the adrenal cortex and thyroid follicular cells in several males at 1000 mg/kg/day (minimal to mild degree). Thyroid follicular hypertrophy was also noted in two males at 150 mg/kg/day at minimal degree. Given the absence of any other treatment-related change in any other parameter assessed in this study, and the mild nature of these findings, these were considered not to represent an adverse effect on the functional integrity of these organs.
No toxicologically significant changes were noted in any of the remaining parameters investigated in this study (i.e. clinical appearance, functional observations, body weight, food consumption, clinical laboratory investigations, macroscopic examination and organ weights.
From the results presented in this report a No Observed Adverse Effect Level (NOAEL) for CORSAIR CLEAR #34 of >=1000 mg/kg/day was established.