Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to guideline; under GLP conditions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1100 (Acute Oral Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
other: EPA OPPTS 870.1000 (Acute toxicity testing background)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Test type:
acute toxic class method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 11-HN (11 alpha-hydroxynorandrostenedione)
- Physical state: solid
- Other: The routine hygienic procedures were sufficient to assure personnel health and safety.

Test animals

Species:
rat
Strain:
other: Wistar rats Crl:WI(Han) (full barrier)
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Recognised animal supplier
- Age at study initiation: 9-10 weeks old
- Weight at study initiation: 145 - 187 g
- Fasting period before study: Prior to test material administration, food was withheld from test animals for 16-19 hours.
- Housing: Housed in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding (lot no. 110811).
- Diet (e.g. ad libitum): Altromin 1324 maintenance diet for rats and mice (lot no. 0815) ad libitum.
- Water (e.g. ad libitum): Tap water (sulphur acidified to a pH value of approximately 2.8) ad libitum.
- Acclimation period: At least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 55 +/- 10
- Air changes (per hr): 10
- Photoperiod: 12 hours light/12 hours dark

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
cotton seed oil
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 300 mg/ml and 2000 mg/ml
- Amount of vehicle (if gavage): 10 ml/kg
- Justification for choice of vehicle: chosen due to its non-toxic characteristics.
- Lot/batch no. (if required): MKBJ0602V

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/ml

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: limited information on test material, for animal welfare reasons the OECD 423 guideline recommends using the starting dose of 300 mg/kg body weight.
Doses:
300 mg/ml, 2000 mg/ml.
No. of animals per sex per dose:
6 (for each dose, animals were split into two groups so that there were 3 animals per group)
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Test animals were observed several times on the day of dosing with special attention during the first 4 hours. Thereafter test animals were observed for clinical signs once daily until the end of the observation period. Body weights were recorded on day 1 (prior to test material administration) and on days 8 and 15.
- Necropsy of survivors performed: yes

Results and discussion

Effect levels
Sex:
female
Dose descriptor:
LD50
Effect level:
> 300 - < 2 000 mg/kg bw
Based on:
test mat.
Mortality:
300 mg/kg bw group: No mortalities were observed in either group.
2000 mg/kg bw: A total of 3 animals died (1 dead in group 1 and 2 dead in group 2).
Clinical signs:
300 mg/kg bw group: reduced spontaneous activity, apathy, recumbency, kyphosis, half eyelid-closure, lethargy, piloerection and bradykinesia.
2000 mg/kg bw group: reduced spontaneous activity, recumbency, lethargy, ataxia, wasp waist, piloerection, abnormal breathing and half-eyelid closure.
Body weight:
Weight gain of surviving animals was within the normal range for this strain.
Gross pathology:
Necropsy of surviving animals showed no treatment-related macroscopic findings. Necropsy of animals not having survived until the end of the observation period showed the following: haemorrhagic duodenum, jejunum and illeum. Test item residue was also observed in one animal.

Applicant's summary and conclusion

Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the conditions of this study, the acute oral median lethal dose (LD50) of the test material in the female Wistar strain rat was estimated to be between 300 and 2000 mg/kg bodyweight.
Executive summary:

The study was performed to assess the acute oral toxicity of the test material in the Wistar strain of rat. The study was performed to GLP and the method was designed to meet the requirements of OECD 423 guideline, EU method B.1 tris, EPA OPPTS 870.1000 and 870.1100 guidelines. A stepwise approach was used to evaluate the toxicity of the test material. Absence or presence of compound-related mortality of the animals dosed at one step determined the next step. Two groups (each of 3 test animals) were used for each dose. The test material was administered orally, after overnight fasting, once only by gavage, as a suspension in cotton seed oil. The test material concentrations in the vehicle were 300 mg/mL and 2000 mg/mL and the administered volume of suspension was 10 mL/kg body weight.Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy after an observation period of 14 days. Clinical observations in the 300 mg/kg dose group included: reduced spontaneous activity, apathy, recumbency, kyphosis, half eyelid-closure, lethargy, piloerection and bradykinesia. Clinical observations in the 2000 mg/kg bw group included: reduced spontaneous activity, recumbency, lethargy, ataxia, wasp waist, piloerection, abnormal breathing and half-eyelid closure. Animals of the 300 mg/kg bw dose group recovered within 24 hours and all test animals survived to the end of the study; a total of 3 test animals in the 2000 mg/kg bw dose group were found dead after 24 hours post-exposure of the test material (1 death in group 1 and 2 deaths in group 2). All surviving animals showed expected gains in bodyweight during the study. No abnormalities were noted at necropsy. The acute oral median lethal dose (LD50) of the test material in the female Wistar strain rat was estimated to be between 300 and 2000 mg/kg bw.