Reaction mass of ethyl (1S,2R,4S)-bicyclo[2.2.1]hept-5-ene-2-carboxylate and ethyl (1R,2R,4R)-bicyclo[2.2.1]hept-5-ene-2-carboxylate

Endpoint summary

Description of key information

The acute oral toxicity of the test substance, TM 09-218, was assessed according to OECD Test Guideline 423 using an acute toxic class method. The acute median lethal oral dose (LD50) to rats of TM 09-218 was greater than 2000 mg/kg body weight.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 17 July 2014 and 14 August 2014.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study is considered to be a reliability 1 as it has been conducted according to OECD Test Guideline 423 using an acute toxic class method and in compliance with GLP.

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

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

Animal supply, acclimatisation and allocation

Healthy nulliparous and non-pregnant female HSD:Sprague Dawley® SD® albino rats were obtained from a reputable supplier.
The animals were allocated without conscious bias to cages within the treatment groups. They were housed in groups of three rats of the same sex.
Each animal was assigned an alpha-numeric code and identified uniquely within the study by tail marking. Each cage label was colour-coded and was identified uniquely with the study number, dose level and animal mark.
The animals were allowed to acclimatise to the conditions described below for at least 5 days before treatment. For those animals selected for this study, their body weights were in the range 148 to 195 g and they were approximately eight to twelve weeks of age prior to dosing (Day 1).

Animal housing, diet and water supply

Animals were housed inside a barriered rodent facility . The facility was designed and operated to minimise the entry of external biological and chemical agents and to minimise the transference of such agents between rooms. The animal room was kept at positive pressure with respect to the outside by its own supply of filtered fresh air, which was passed to atmosphere and not re-circulated. The temperature and relative humidity controls were set to maintain the range of 19 to 23°C and 40 to 70% respectively. Any minor deviations from these ranges would not have had an adverse effect
on the animals and would not affect the integrity or validity of the study. Artificial lighting was controlled to give a cycle of 12 hours continuous light and 12 hours continuous dark per 24 hours. Environmental parameters are archived with the departmental raw data. Periodic checks were made on the number of air changes in the animal rooms. Temperature and humidity were monitored daily. Alarms were activated if there was any failure of the ventilation system, or temperature limits were exceeded. A stand-by electricity supply was available to be automatically brought into
operation should the public supply fail.
The cages were solid bottomed polycarbonate cages with a stainless steel mesh lid. Each cage contained a quantity of autoclaved softwood bark-free fibre bedding. Cages, food hoppers, water bottles and bedding were changed at appropriate intervals. The animals were allowed free access to a standard rodent diet (Rat and Mouse No. 1 Maintenance Diet), except for overnight prior to and approximately four hours after dosing. This diet contained no added antibiotic or other chemotherapeutic or prophylactic agent. Potable water taken from the public supply was freely available via polycarbonate bottles fitted with sipper tubes.
Each cage of animals was provided with an Aspen chew block for environmental enrichment. Chew blocks were provided throughout the study and were replaced when necessary. Each cage of animals was provided with a plastic shelter for environmental enrichment, which was replaced at the same time as the cages. Each batch of diet was analysed routinely by the supplier for various nutritional components and chemical and microbiological contaminants. Supplier’s analytical certificates were scrutinised and approved before any batch of diet was released for use. The quality of the water supply is governed by regulations published by the Department for Environment, Food and Rural Affairs. Certificates of analysis were received routinely from the water supplier.
Certificates of analysis were received routinely from the supplier of the chew blocks. Since the results of these various analyses did not provide evidence of contamination that might have prejudiced the study, they are not presented. No other specific contaminants that were likely to have been present in the diet or water were analysed, as none that may have interfered with or prejudiced the outcome of the study was known.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

Vehicle
The vehicle used on this study was corn oil.

Formulation
The test substance was formulated at concentrations of 30 or 200 mg/mL in the vehicle and
administered at a volume of 10 mL/kg body weight.
The test substance formulations were prepared on the day of dosing.
The absorption of the test substance was not determined.
Determination of the homogeneity, stability and purity of the test substance or test substance
formulations were not undertaken as part of this study.
Detailed records of test substance usage were maintained. The amount of test substance
necessary to prepare the formulations and the amount actually used were determined on each
occasion. The difference between these amounts was checked before the formulations were
dispensed.

Administration
The appropriate dose volume of the test substance was administered to each rat by oral
gavage using a plastic syringe and plastic catheter.
A record of the weight of each formulation dispensed and the amount remaining after dosing
was made. The balance of these two weights was compared with the predicted usage as a
check that the doses had been administered correctly.
Formulations were stirred before and throughout the dosing procedure.

Doses:

300 and 2000 mg/kg body weight

No. of animals per sex per dose:

Three females per group

Control animals:

no

Details on study design:

Mortality
Cages of rats were checked at least twice daily for any mortalities.

Clinical observations
Animals were observed soon after dosing and at frequent intervals for the remainder of Day 1. On subsequent days, animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15 - morning only). The nature and severity, where appropriate, of the clinical signs and the time were recorded at each observation. All animals were observed for 14 days after dosing.

Body weight
The weight of each rat was recorded on Days 1 (prior to dosing), 8 and 15. Individual weekly body weight changes and group mean body weights were calculated.

Method of kill
All animals were humanely killed on Day 15 by carbon dioxide asphyxiation.

Macroscopic pathology
All animals were subject to a macroscopic examination which consisted of opening the cranial, thoracic and abdominal cavities. The macroscopic appearance of all examined organs was recorded.

Statistics:

The computer systems that were used on this study to acquire and quantify data include:
Liberate Global: In-house system used for reporting in-life.
Xybion Pristima: Used for in-life and necropsy data collection and pharmacy test substance management.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths during the study.

Clinical signs:

other: Clinical signs observed for animals dosed at 300 mg/kg bodyweight comprised piloerection (An. Nos. 1 - 6) and perianal staining (An. Nos. 4, 5). Clinical signs observed for animals dosed at 2000 mg/kg bodyweight comprised elevated gait (An. Nos. 7 - 10),

Gross pathology:

No abnormalities were noted in any animal at the macroscopic examination at study termination on Day 15.

Other findings:

No abnormalities were noted in any animal at the macroscopic examination at study termination on Day 15.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute median lethal oral dose (LD50) to rats of TM 09-218 was demonstrated to be greater than 2000 mg/kg body weight.

Executive summary:

The acute oral toxicity of the test substance, TM 09-218, was assessed according to OECD Test Guideline 423 using an acute toxic class method. The acute median lethal oral dose (LD50) to rats of TM 09-218 was greater than 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for selection of acute toxicity – oral endpoint
The study was conducted on the target substance in vivo, in an appropriate test species and according to internationally recognised guidelines.

Justification for classification or non-classification

Substances can be allocated to one of four toxicity categories based on acute toxicity by the oral, dermal or inhalation route according to the Globally Harmonized Classification System and Regulation (EC) No. 1272/2008, relating to the Classification, Labelling and Packaging of Substances and Mixtures. Acute toxicity values are expressed as approximate LD50 or LC50 (inhalation) values. 

A test substance is classified according to one of these four toxicity categories when the acute LD50 value is ≤ 2000 mg/kg for exposure via the oral and dermal routes.

 

An in vivo study performed according to internationally recognised guidelines and conducted according to GLP gave an acute oral LD50 of > 2000 mg/kg and therefore the test substance, TM 09-218, is not classified for acute oral toxicity.