2-[1-(ethylsulfonyl)azetidin-3-ylidene]acetonitrile

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 Feb 2012 to 07 March 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

OECD Guideline 423. Acute Oral Toxicity - Acute Toxic Class Method, December 2001.

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-[1-(ethylsulfonyl)azetidin-3-ylidene]acetonitrile

EC Number:

691-838-1

Cas Number:

1187595-85-2

Molecular formula:

C7H10N2O2S

IUPAC Name:

2-[1-(ethylsulfonyl)azetidin-3-ylidene]acetonitrile

Test material form:

solid: particulate/powder

Details on test material:

Lot no: 4500566148-0003

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Justification for Test System and Number of Animals
The Wistar Han rat was chosen as the animal model for this study as recognized by international guidelines as a recommended test system. The test method and number of animals were based on the test guidelines.

Environmental Acclimation
The animals were allowed to acclimate to the Test Facility toxicology accommodation for at least 5 days before the commencement of dosing.

Husbandry
Housing
Animals were housed in suspended wire cages which conform to the size recommendations in Guide for the Care and Use of Laboratory Animals DHEW {NIH). Rats were housed 5/sexlcage prior to dosing and 3/sex/cage following dosing. Absorbent paper bedding, placed beneath the cage, will be changed at least three times/week. The animal room, reserved exclusively for rodents on acute tests. is temperature controlled. has a 12-hour light/dark cycle. and will be kept clean and vermin free.

Food
Fresh PMI Rat Chow (Diet #5012) was available except 16 - 20 hours prior to dosing

Water
Ad Libitum

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Remarks:

2%

Details on oral exposure:

Experimental Design
The toxicity of the test item was assessed by stepwise treatment of groups of 3 females. The absence or presence of mortality of animals dosed at one step determined the next step, based on the test procedure defined in the guidelines. The onset, duration and severity of the signs of toxicity were taken into account for determination of the time interval between the dose groups. The first group was treated at a dose level of 300 mg/kg. Based on the results, one additional group was dosed at 2000mg/kg.

Administration of Test item
The test article was mixed with 2% methylcellulose solution to make dosing by gavage possible. The dose was based on the dry weight of the test article. A single dose was administered orally by syringe and dosing needle at a dose level of 300mg/kg to three female and three male rats and 2000mg/kg to three female rats.

Doses:

2000mg/kg and 300 mg/kg

No. of animals per sex per dose:

3 females per dose

Control animals:

no

Details on study design:

Rationale for Vehicle
Trial preparations were performed to select the suitable vehicle and to establish a suitable formulation procedure. These trials were not performed as part of this study and these preparations were not used for dosing. Raw Data of these trials will be retained by the Test Facility.

Test Item Characterization
The Sponsor provided to the Test Facility documentation of the identity, purity, composition, and stability for the test item. The characterization of the test item was conducted in a sponsor or sponsor subcontractor quality environment.

Reserve Samples
For each batch (lot) of test item, a reserve sample (about 0.5 gram) was collected and maintained under the appropriate storage conditions by the Test Facility. The sample will be destroyed after the expiry date.

Test and Reference Item Inventory and Disposition
Records of the receipt, distribution, and storage of test item were maintained. With the exception of reserve samples, all unused Sponsor-supplied test item will be discarded or returned to the Sponsor after completion of the scheduled program of work. Records of the decisions made will be kept at the Test Facility.

Preparation of Test Item
Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements. The dosing formulations were stirred until and during dosing. Any residual volumes were discarded.

Sample Collection and Analysis
Analysis of test item in vehicle for concentration, stability, homogeneity was not performed.

Terminal Procedures
Post Mortem – Survivors were humanely sacrificed using CO2 and all animals were examined for gross pathology following study termination

Statistics:

In-life Procedures, Observations, and Measurements

Mortality/Moribundity Checks
Throughout the study, animals were observed for general health/mortality and moribundity at 15 minutes(± 5 min), 1, 2 & 4 hours postdose and once daily thereafter for 14 consecutive days for toxicity and pharmacological effects and twice daily for mortality

Clinical Observations

Body Weights
Were recorded immediately pretest, weekly and at death or study termination in the survivors..

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Three females died following the single 2000 mg/kg oral dose. The deaths occurred 4 hours post dose through Day 2.

Clinical signs:

other: Abnormal physical signs including thinning of the fur (on lower back) and enophthalmos were observed in the 300 mg/kg group. In the 2000 mg/kg group excess salivation, piloerection, lethargy, tremors, convulsions, and diarrhea were observed prior to death

Gross pathology:

The gross necropsy of all animals revealed no observable abnormalities in the 300 mg/kg group.
The gross necropsies revealed red staining and wetness of the nose/mouth area, wetness of the anogenital area, darker than normal lungs, darkened areas of the lungs, and abnormalities of the gastrointestinal tract in the 2000mg/kg group.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Compound 3017431, Lot# 4500566148-0003 is considered to be in Acute Toxic Category 4. The oral LD50 is greater than 300 mg/kg, but less than 2000 mg/kg of body weight in rats.

Executive summary:

Initially, three healthy female Sprague Dawley rats were dosed orally with Compound 3017431, Lot# 4500566148-0003 at 300 mg/kg. An additional three healthy males were dosed as a confirmatory group at 300 mg/kg. Since there was no toxicity noted at this level, an additional three healthy female Sprague Dawley rats were dosed orally at 2000 mg/kg. Due to mortality at this level, dosing was discontinued. The rats were observed at 15 minutes, 1, 2 and 4 hours post dose and daily for 14 days for toxicity and pharmacological effects. Animals were observed twice daily for mortality. Body weights were recorded immediately pretest, weekly, at death and at termination in the survivors. All animals were examined for gross pathology. The test article was assigned to a toxic category based on the mortality response noted.

Summary: 300 mg/kg: Three females and three males survived the single 300 mg/kg oral dose. Abnormal physical signs including thinning of the fur (on lower back) and enophthalmos were observed. All of the females gained body weight by Day 14.  All of the males lost body weight between Day 7 and Day 14. The gross necropsy of all animals revealed no observable abnormalities.

2000 mg/kg: Three females died following the single 2000 mg/kg oral dose. The deaths occurred 4 hours post dose through Day 2. Excess salivation, piloerection, lethargy, tremors, convulsions, and diarrhea were observed prior to death. Body weight loss was observed at death in all three animals. The gross necropsies revealed red staining and wetness of the nose/mouth area, wetness of the anogenital area, darker than normal lungs, darkened areas of the lungs, and abnormalities of the gastrointestinal tract.