2H-3-Benzazepin-2-one, 3-[2-(1,3-dioxolan-2-yl)ethyl]-1,3-dihydro-7,8-dimethoxy-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

4 september 2017 to 18 october 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was performed to assess the acute oral toxicity of the test item in the Wistar strain rat.
Following a sighting test at dose levels of 2000 mg/kg, 300 mg/kg and 50 mg/kg, a further group of four fasted females was given a single oral dose of test item, as a suspension in arachis oil BP, at a dose level of 50 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Test material

Test material information

Constituent 1

Reference substance name:

617-898-0

EC Number:

617-898-0

Cas Number:

866462-52-4

Molecular formula:

C17 H21 N O5

IUPAC Name:

617-898-0

Test material form:

solid: particulate/powder

Details on test material:

Off white powder

Specific details on test material used for the study:

Batch: 18126645
Purity: 97.2%
Physical state/Appearance: white powder
Expiry Date: 01 December 2018
Storage Conditions: room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Animal Information :
Female Wistar (RccHan™:WIST) strain rats were supplied by Envigo RMS (UK) Limited, Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non-pregnant. After an acclimatization period of at least 5 days the animals were selected at random and given a number unique within the study by indelible ink-marking on the tail and a number written on a cage card. At the start of the study the animals were 8 to 12 weeks of age. The body weight variation did not exceed ±20% of the mean body weight at the start of treatment.
Animal Care and Husbandry :
The animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes. With the exception of an overnight fast immediately before dosing and for approximately 3 to 4 hours after dosing, free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Envigo RMS (UK) Limited, Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analyzed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.
The temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.
The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Doses:

2000, 300 and 50 mg/kg

No. of animals per sex per dose:

1 animal per dose then 4 females for the second group tested at 50 mg/kg

Details on study design:

In the absence of data regarding the toxicity of the test item, 2000 mg/kg was chosen as the starting dose.
A single animal was treated as follows:
Dose Level (mg/kg) : 2000 - Concentration (mg/mL) : 200 - Dose Volume (mL/kg) : 10 - Number of Rats Female : 1

Due to mortality at a dose level of 2000 mg/kg, an additional animal was treated as follows:
Dose Level (mg/kg) : 300 - Concentration (mg/mL) : 30 - Dose Volume (mL/kg) : 10 - Number of Rats Female : 1

Due to mortality at a dose level of 300 mg/kg, an additional animal was treated as follows:
Dose Level (mg/kg) : 50 - Concentration (mg/mL) : 50 - Dose Volume (mL/kg) : 10 - Number of Rats Female : 1

In the absence of mortality and toxicity at a dose level of 50 mg/kg, an additional group of animals was treated as follows:
Dose Level (mg/kg) : 50 - Concentration (mg/mL) : 5 - Dose Volume (mL/kg) : 10 - Number of Rats Female : 4

A total of five animals were therefore treated at a dose level of 50 mg/kg in the study.
All animals were dosed once only by gavage, using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to the fasted body weight at the time of dosing. Treatment of animals was sequential. Sufficient time was allowed between each dose group to confirm the survival of the previously dosed animals.
Clinical observations were made 30 minutes, 1, 2, and 4 hours after dosing and then daily for up to 14 days. Morbidity and mortality checks were made twice daily, early and late during normal working days, and once daily at weekends and public holidays.
Individual body weights were recorded on Day 0 (the day of dosing) and on Days 7 and 14 or at death.
At the end of the observation period the surviving animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 50 - < 300 mg/kg bw

Based on:

test mat. (total fraction)

Mortality:

The animals treated at a dose levels of 300 mg/kg and 2000 mg/kg were killed for humane reasons, one or six days day after dosing, due to the occurrence of clinical signs of toxicity that approached the severity limit set forth in the UK Home Office Project Licence. There were no deaths at a dose level of 50 mg/kg.

Clinical signs:

Signs of systemic toxicity noted in the animals treated at dose levels of 300 mg/kg and 2000 mg/kg were hunched posture, pilo-erection, dehydration, hypothermia, tiptoe gait, emaciation, pallor of the extremities and lethargy. There were no signs of systemic toxicity noted at a dose level of 50 mg/kg.

Body weight:

Surviving animals showed expected gains in body weight.

Gross pathology:

Abnormalities noted at necropsy of the animal treated at a dose level of 2000 mg/kg were patchy pallor of the liver, pale and gaseous small and large intestines and white material present in the stomach. Abnormalities noted at necropsy of the animal treated at a dose level of 300 mg/kg were pale liver and pale kidneys. No abnormalities were noted at necropsy of animals treated at a dose level of 50 mg/kg.

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was estimated to be in the range of 50 - 300 mg/kg body weight (Globally Harmonized Classification System Category 3).