Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
14 May - 03 June 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

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
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1100 (Acute Oral Toxicity)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000, including the most recent partial revisions.
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Test type:
acute toxic class method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: bulk
Details on test material:
- Name of test material (as cited in study report): Anhydrothymidine
- Substance type: White powder
- Physical state: powder
- Analytical purity: 99.7%
- Purity test date: not stated
- Lot/batch No.: 073904/05
- Expiration date of the lot/batch: 11 December 2008
- Stability under test conditions: stable
- Storage condition of test material: At room temperature in the dark

Test animals

Species:
rat
Strain:
Wistar
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Strain: Rat, Wistar strain Crl:WI (Han) (outbred, SPF-Quality)
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approx. 11-12 weeks old
- Weight at study initiation: 171-201g
- Fasting period before study: Food was withheld overnight (for a maximum of 20 hours) prior to dosing until 3-4 hours after administration of the test substance.
- Housing: Group housing of 3 animals per cage in labeled Macrolon cages (MIV type; height 18 cm.) containing sterilized sawdust as bedding material and paper as cage-enrichment.
- Diet (e.g. ad libitum): Free access to pelleted rodent diet
- Water (e.g. ad libitum): Free access to tap water
- Acclimation period: at least 5 days before start of treatment under laboratory conditions


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.3 – 21.3
- Humidity (%): 31 – 80
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg (10 mL/kg) body weight.


DOSAGE PREPARATION (if unusual): The formulations (w/w) were prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level.


CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose:
Doses:
2000 mg/kg b.w.
No. of animals per sex per dose:
6 (2 groups of three females in a stepwise manner)
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality- Twice daily. Body weight- Days 1 (pre-administration), 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology

Results and discussion

Effect levels
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
No mortality occurred.
Clinical signs:
Hunched posture was noted among in the animals Day 1.
Body weight:
The body weight gain shown by the animals over the study period was considered to be similar to that expected of normal untreated animals of the same age and strain.
Gross pathology:
No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The oral LD50 value of the test substance in Wistar rats was established to exceed 2000 mg/kg body weight.
According to the OECD 423 test guideline the LD50 cut-off value was considered to exceed 5000 mg/kg body weight.