Registration Dossier

Toxicological information

Repeated dose toxicity: oral

Currently viewing:

Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 3 december 1992 To 31 december 1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline 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:
1993
Report Date:
1993

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Deviations:
yes
Remarks:
: No satellite groups were used.
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
: No satellite groups were used.
Principles of method if other than guideline:
Not applicable.
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Physical state: white powder
- Storage condition of test material: room temperature under silica gel

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River (U.K.) Limited, Manston, Kent.
- Age at study initiation: 5-6 weeks old
- Weight at study initiation: 133-174 g (females), 128-150 g (males)
- Fasting period before study: no data
- Housing: five by sex in cages
- Diet : ad libitum
- Water : ad libitum
- Acclimation period: eight days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-22
- Humidity (%): 35-74
- Air changes (per hr): at least 15
- Photoperiod : 12 hrs dark / 12 hrs light


IN-LIFE DATES: no data

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: The test material was prepared at the appropriate concentrations, as a solution in distilled water. the stability
and homogeneity of the test material formulations were determine by Safepharm Analytical Laboratory. Results show the formulation to be stable for at least 11 days. Formulations were therefore prepared weekly and stored at 4 °C in the dark. The analysis of formulations indicate that the prepared formulations were within +/- 1 % of the nominal concentration.



Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The ITC 288 concentration in the test material formulations was determined colorimetrically for the weekly test material formulations and by ion chromatography for the stability of test material formulations.
Duration of treatment / exposure:
28 days
Frequency of treatment:
daily
Doses / concentrations
Remarks:
Doses / Concentrations:
150, 400, 1000 mg/kg/day
Basis:
actual ingested
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The dose levels were chosen based on the results of a range-finding study.
No satellite groups were used.
Positive control:
No

Examinations

Observations and examinations performed and frequency:
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: all animals were examined for overt signs of toxicity, ill-health or behavioural change immediately before dosing and one and five hours after dosing during the working week. Animals were observed immediately before dosing and one hour after dosing at weekends and public holidays.


BODY WEIGHT: Yes
- Time schedule for examinations: Bodyweights were recorded on the day before the start of treatment (day 0) and on days 7, 14, 21 and 28. Bodyweights were also recorded at necropsy.


FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes


OPHTHALMOSCOPIC EXAMINATION: No data


HAEMATOLOGY: Yes
- Time schedule for collection of blood: day 28
- Anaesthetic used for blood collection: No data
- Animals fasted: No
- How many animals: all animals
- Parameters examined: Haematocrit, haemoglobin, erythrocyte count, total leucocyte count, differential leucocyte count, platelet count, mean corpuscular haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin concentration.


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day 28
- Animals fasted: No
- How many animals: all animals
- Parameters examined: blood urea, total protein, albumin, albumin/ globulin ratio, sodium, potassium, chloride, calcium, inorganic phosphorus, creatinine, alkaline phosphatase, alanine aminotransferase, asparte aminotransferase, glucose, total bilirubin


URINALYSIS: No



NEUROBEHAVIOURAL EXAMINATION: No data



Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Other examinations:
None
Statistics:
Absolute and relative organ weights, haematological and blood chemical data were analysed by one way analysis of variance incorporating 'F-max' test for homogeneity of variance. Data showing heterogeneous variances were analysed using Kruskal wallis non-parametric analysis of variance and Mann Whitnay U-test

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Clinical signs were only detected in high dose females from day 23 on wards).
Mortality:
mortality observed, treatment-related
Description (incidence):
Clinical signs were only detected in high dose females from day 23 on wards).
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
These changes were considered as not adverse and not related to ITC 288/S treatment.
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
There were no treatment-related deaths. One 400 mg/kg/day male was found dead on day 14.
Clinical signs (pilo-erection, salivation, red/brown staining of the fur) were only detected in high dose females (all females on day 28).
BODY WEIGHT AND WEIGHT GAIN
No adverse effects on bodyweight gain were detected. All animals showed normal bodyweight increases throughout the study period.

FOOD EFFICIENCY
The food efficiency was similar between treated and control rats.

HAEMATOLOGY
There were no treatment-related changes in the haematological parameters measured. A statistically significant reduction in high dose male monocyte counts and high dose female mean corpuscular haemoglobin and mean corpuscular volume were detected in comparison with controls. All values were within the respective normal ranges and, in isolation, were considered to be without toxicological significance. Clotting time was elevated in high dose animals of both sexes and in low dose males but no convincing dose relationship was elicited and the slight increase was considered to be fortuitous and not toxicologically important. The other minor statistically significant difference detected was confined to a reduction in low dose male eosinophil counts which showed no dose-related response.

CLINICAL CHEMISTRY
Alkaline phosphatase levels were elevated in high dose animals of either sex and two males showed levels outside the normally expected range. A slight but statistically significant increase was also noted in levels of this enzyme for low dose males compared with controls but this was not part of a dose-related response and was considered to be fortuitous. A statistically significant reduction in plasma albumin was detected in intermediate and high dose males in comparison with controls. A clear dose relationship was not evident and the reduction was, therefore considered not to be toxicologically significant. Alanine aminotransferase showed a statistically significant reduction in high dose males in comparison with controls, however, all values were entirely normal and a reduction in this parameter connot be considerd to be toxicologically significant. The other minor statistically significant differences detected between test and control groups were confined to low and intermediate dose animals and, as such, showed no dose-related response.

ORGAN WEIGHTS
There were no changes in the organ weights measured which could be considered attributable to treatment with the test material. Statistically significant reductions were observed (see Table 7.5.1/2 ):

* In the males: ↓ in absolute liver weight at 1000 mg/kg bw.
↓ in relative liver weight at 400 and 1000 mg/kg bw
↓ in absolute heart weight at 1000 mg/kg bw.
* In the females: ↓ in absolute spleen weight at 1000 mg/kg bw.
↓ in relative spleen weight at 1000 mg/kg bw.
The incidence of these findings was within the ranges for historical control for rats of this strain and age. Given these results, these changes were not considered treatment related .

GROSS PATHOLOGY
No treatment-related macroscopic abnormalities were detected. The incidental findings recorded at necropsy were consistent with those normally expected in laboratory maintened rats. The decedent from the intermediate dose group had been severely cannibalised, however, the macroscopic abnormalities noted were those of normal post mortem changes and were not indicative of toxicity.

HISTOPATHOLOGY:
No treatment-related changes were observed. All morphological changes were those commonly observed in laboratory maintained rats of the age and strain employed and, since there were no differences in incidence or severity between control and treatment groups, all were considered to be without toxicological significance.







Effect levels

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: increased phosphatase alkaline in both sex and on clinical signs observed in females at this dose level (all females on day 28).

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

Table 7.5.1/2: Male Body weight, absolute and relative liver weight (control, medium and high dose)

 

Treated groups (mg/kg bw/day)

Body weight at necropsy (g)

AbsoluteLiverweight(g)

Relative Liver weight (%)

Control

359

16.6486

4.6375

327

13.4728

4.1201

392

17.8332

4.5493

375

15.0909

4.0242

368

13.9197

3.7825

400

394

16.4081

4.1645

301

11.7971

3.9193

 -

 -

 -

342

13.3880

3.9146

323

10.7487

3.3278

1000

285

10.2090

3.5821

379

14.6425

3.8635

362

14.1805

3.9173

293

10.6518

3.6354

349

13.2263

3.7898

-: animal died.

Applicant's summary and conclusion

Conclusions:
Under the test conditions of this study, a slight change in physical conditions and an increase in plasma alkaline phosphatase levels were observed. However,
no changes in survival or body weight, no gross or microscopic pathologic changes related to ITC 288/S consumption were measured. These changes were considered as transient and cannot be regarded as significant effects on the health of the animals.
Because no significant relevant toxic effects were noted in this study, the NOAEL >= 1000 mg/kg bw/day was identified.
Executive summary:

In a 28 day sub-acute oral toxicity study (Coles, 1993), ITC 288 was administered by gavage to three groups, each of five male and five female Sprague-Dawley CD strain rats, at dose levels of 150, 400 and 1000 mg/kg/day. A control group of five males and five females was dosed with vehicle alone (distilled water). Clinical signs, bodyweight, food and water consumptions were monitored during the study. Haematology and blood chemistry were evaluated for all animals at the end of the study. All animals were subjected to a gross necropsy examination and a limited histopathological evaluation of tissues was performed. There were no treatment-related deaths. High dose females showed signs of pilo-erection, increased salivation and red/brown staining of the fur from day 23 onwards. High dose males and the remaining dose groups showed no clinically observable signs of toxicity throughout the study period. No adverse effects on bodyweight gain were noted. Food and water consumption in test animals were comparable with that seen in controls. No treatment-related effects on haematology were detected. Plasma alkaline phosphatase levels were elevated in high dose animals of either sex but there were no other changes that could be considered toxicologically significant. At necropsy, no treatment-related macroscopic abnormalities were detected. No treatment-related effects were effected on organ weights or histopathology. Under the conditions of this test, oral administration of ITC 288 to rats for a period of 28 consecutive days, at dose levels of up to 1000 mg/kg/day, resulted in a slight effects at the top dose level. These effects were confined to a slight change in physical conditions and an increase in plasma alkaline phosphatase levels, which, cannot be regarded as significant effects on the health of the animals. No such effects were detected in the 400 or 150 mg/kg/day dose groups. A NOAEL >= 1000 mg/kg/day were identified.