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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08 March 1999 - 17 January 2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
- Principle of test: determination of the maximum non-lethal oral dose of the test substance
- Short description of test conditions: similar to existing guidelines, except that there was no fasting period and dosing was not performed in a step-wise manner
GLP compliance:
yes
Remarks:
(but without QA)
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Reference substance name:
(2S)-2-(2-oxo-4R-propylpyrrolidin-1-yl)butanamide
Cas Number:
357336-20-0
IUPAC Name:
(2S)-2-(2-oxo-4R-propylpyrrolidin-1-yl)butanamide
Test material form:
solid: particulate/powder
Details on test material:
- Description: White to off-white powder
- Storage conditions: At room temperature in the dark

Test animals

Species:
rat
Strain:
other: Hsd Brl Han : WIST
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan, Horst, The Netherlands
- Age at study initiation (prior to dosing): approx. 6-7 weeks
- Weight at study initiation (prior to dosing): 155-175 g (males), 119-138 g (females)
- Fasting period before study: no
- Housing: from arrival, the animals were housed up to 3 rats per cage in N8 suspended metallic cages (20x40x21 cm) with wire mesh floor
- Diet: SDS RM1 (E) SQC, Essex, England, ad libitum
- Water: ultraviolet-treated tap water, ad libitum
- Acclimation period: minimum of 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22
- Humidity (%): 42-62
- Photoperiod (hrs dark / hrs light): 12/12
- Air changes (per hr): 15-20

IN-LIFE DATES: From: 16 March 1999 To: 30 March 1999

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
(sterile pyrogen-free water for injection (Baxter S. A., Lessines, Belgium))
Details on oral exposure:
GAVAGE METHOD: suitable graduated syringe and a semi-rigid catheter (Marquat type V010670)

Frequency: single dosage, on Day 1

DOSE VOLUME APPLIED
20 mL/kg body weight

DOSAGE PREPARATION
A formulation of 100 mg/mL was prepared by dissolving the test substance in the vehicle. Additional formulations of 50 and 25 mg/mL were prepared by direct dilution of the high concentration solution with vehicle. Formulations were stored protected from light and at room temperature until use. They were administered within 2 hours after preparation.
Doses:
500, 1000 and 2000 mg/kg bw
No. of animals per sex per dose:
3
Control animals:
yes
Remarks:
(treated with vehicle)
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations:
Mortality: twice a day during working days and once a day on weekends and on the day of sacrifice
Clinical signs: on day 1, before dosing, and approx. 30 min., 1, 2 and 6 hours after dosing. Thereafter on days 2, 8 and 14.
- Frequency of weighing: on days 1 (prior to dosing), 2, 4, 6, 8, 10, 12, 14 and prior to necropsy (day 15)
- Necropsy of survivors performed: yes
- Other examinations performed: food consumption

Results and discussion

Effect levelsopen allclose all
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 1 000 - < 2 000 mg/kg bw
Based on:
test mat.
Key result
Sex:
male
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
- At 2000 mg/kg bw, all females were sacrificed for ethical reasons 2 hours after dosing and all males survived
- No mortality was found at 500 and 1000 mg/kg bw for males and females
Clinical signs:
- At 2000 mg/kg bw the females presented prior to sacrifice decreased muscular tone, lying on the abdomen and/or side, reduced activity, loss of pinching, righting and palpebral reflexes, piloerection, slow breathing, pupil diameter increased and/or palpebral closing.
- At 2000 mg/kg bw, clinical signs observed on Day 1 among the males were decreased muscular tone and unsteady gait, unstable posture and soiled urogenital area. Males had recovered by Day 2.
- At 1000 mg/kg bw, one male had a decreased muscular tone on Day 1 at 1 h post-dose. One female showed unstable posture, abnormal and unsteady gait and piloerection; another female showed soiled urogenital area. These animals recovered 24 hours after dosing.
Body weight:
All surviving animals gained the expected body weight.
Gross pathology:
At 2000 mg/kg, necropsy of females sacrificed for ethical reasons revealed a white film on the glandular mucosa of the stomach associated for one female with multiple red foci (pinpoint) in the pyloric area and in the duodenum. Red discoloration of the lungs was observed in the third female.
Other findings:
Food consumption was slightly reduced from day 1 to 2 in males dosed at 2000 and 1000 mg/kg bw, without an effect on bodyweight.

Applicant's summary and conclusion

Interpretation of results:
other: Category 4 based on GHS and CLP criteria
Conclusions:
In an acute oral toxicity study in rats, an LD50 of >1000 - < 2000 mg/kg bw in female rats and an LD50 of >2000 mg/kg bw in male rats was determined.
Executive summary:

In an acute oral toxicity study, rats (3/sex/dose) were exposed to 0, 500, 1000 and 2000 mg/kg bw, using water as vehicle. The animals were observed for 14 days following dosing. No mortalities occurred at 500 and 1000 mg/kg bw. At 2000 mg/kg bw, all females were sacrificed for ethical reasons 2 hours after dosing and all males survived. Clinical signs noted at 1000 mg/kg bw and above included decreased muscular tone, unstable posture, unsteady gait, piloerection and soiled urogenital area. The surviving animals recovered by day 2. Based on the results of this study, an LD50 of >1000 - < 2000 mg/kg bw in female rats and an LD50 of >2000 mg/kg bw in male rats was determined.