Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20-Jan-1992 t0 13-May-1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant and preformed in accordance with EEC-Directive 84-449, Annex V, Part B 1.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
other: EEC-Directive 84-449, Annex V, Part B 1
Deviations:
yes
Remarks:
Temperatured was lower on days -1, 0 and 3. There was a power failure one day before the end of the study. None of these deviations are considered to have affected the integrity of the study.
Qualifier:
according to
Guideline:
other: Solvay Duphar standard operating procedure TDS 026
Deviations:
yes
Remarks:
Temperature >18 but <19 was observed on days -1, 0 and 3 of the study. Power failure resulted in the light being switched on one hour later on the final day of the study.
GLP compliance:
yes (incl. certificate)
Test type:
acute toxic class method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Solid

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
Test animals
SPF-derived Hsd/Cpb:WU Wistar rats were obtained from Harlan/CPS, Zeist, The Netherlands. Male rats weighed 175-200 g and females 150-175 g at arrival.

Animal care
The rats were housed continuously in Macrolon cages with two or three animals per cage. The rats had free access to food (a standard laboratory diet RHM-TM, Hope Farms, Woerden, The Netherlands), except for a period of about 18 hours prior to dosing until 6 hours after dosing. Water was available ad libitum. The acclimatisation period was 5 days. Animals were housed in room no. 408, CDA IV, with the following animal room conditions:

Temperature: 18-25°C
Relative humidity: 48-70%
Artificial light: from 7 a.m. till 7 p.m
Radio-sound: 24 hours per day
Ventilation: approximately 16 air changes per hour.



Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: 1.25% tragacanth solution in distilled water
Details on oral exposure:
- Concentration in vehicle: Retroketal, a white solid material, was suspended in a 1.25% tragacanth solution in distilled water. The final concentration was 0.2 g/ml. The actual concentration and the stability of retroketal in the vehicle were not checked using analytical methods, but the test suspension was used immediately after preparation.
- Lot/batch no.: RK149A3
- Purity: 87.4%

Dose selection was a single oral dose of 2000 mg/kg.
Doses:
Single oral dose of 2000 mg/kg
No. of animals per sex per dose:
5/sex/group
Details on study design:
- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: The animals were weighed one day before dosing, at the day of dosing and at 2, 7 and 14 days after treatment. Any sign of intoxication occurring during the 14-day observation period was recorded. Gross post-mortem examination was done on all rats at the end of the 14-day observation period.

Clinical signs
The rats were observed from 0-0.5 hour and at 1.5, 3, 6 and 27 hours after application and thereafter once on each day till the end of the experiment. Any sign of intoxication which could be ascertained by observation and manipulation of the rats during the 14-day observation period was recorded.

Autopsy
At the end of the experiment, the rats were killed by ether inhalation and an autopsy was performed that included inspection of the external appearance, the cervical area, the thoracic and abdominal cavities.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
None of the animals died after a single oral dose of 2000 mg/kg of retroketal. Decreased locomotor activity, decreased respiratory rate, abnormal gait and posture were observed in males, but not in females. The time of onset of the first signs was between 0.5 and 1.5 hours. Signs were slight in intensity and had disappeared by 27 hours.
Clinical signs:
The clinical signs observed in males were mostly indicative of effects on motor coordination (decreased locomotor activity, abnormal gait and posture). In female rats no clinical signs were observed.
Body weight:
Fasting on the day prior to dosing caused a small weight loss in all animals. Oral administration of 2000 mg/kg of retroketal had no effect on mean body weights and weight-gains of male and female rats during the observation period.
Gross pathology:
At autopsy 14 days after dosing no abnormalities were noted for any male animal. One female rat showed a dilated uterus. Dilatation of the uterus is considered to be a physiological process within the oestrus cycle, which is routinely noticed in approximately 1 out of 5 female animals. Therefore, this finding was considered not to be treatment-related.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Oral administration of a single dose of 2000 mg/kg of retroketal caused no mortalities among male and female rats during the 14-day observation period. Therefore, the 14-day oral LD50 is greater than 2000 mg/kg in rats.

The clinical signs observed in males were mostly indicative of effects on motor coordination (decreased locomotor activity, abnormal gait and posture). In female rats no clinical signs were observed.

A single oral dose of 2000 mg/kg of retroketal had no effect on mean body weight-gains of male and female rats.

At autopsy, no treatment-related abnormalities were seen in male and female rats.