(1R,4S,4aR,8aS)-9-(dichloromethylidene)octahydro-1,4-methanonaphthalene-5,8-dione

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2011-04-19 to 2011-05-19 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Version / remarks:

from 2008

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

from December 2002

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

up-and-down procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(1R,4S,4aR,8aS)-9-(dichloromethylidene)octahydro-1,4-methanonaphthalene-5,8-dione

EC Number:

700-729-0

Cas Number:

1369500-14-0

Molecular formula:

C12H12Cl2O2

IUPAC Name:

(1R,4S,4aR,8aS)-9-(dichloromethylidene)octahydro-1,4-methanonaphthalene-5,8-dione

Details on test material:

- Physical state: Brown powder
- Stability under test conditions: not reported
- Storage condition of test material: At room temperature (20 ± 5 °C), light protected

Test animals

Species:

rat

Strain:

other: RccHan:WIST(SPF)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 10 weeks
- Weight at study initiation: 181.8 - 185.7 g
- Fasting period before study: 17 to 22 hours before treatment, with free access to water
- Housing: In groups of up to five in Makrolon type-4 cages during acclimatization. Individually in Makrolon type-3 cages during treatment and observation. Cages were equipped with wire mesh tops and standard softwood bedding including paper enrichment during treatment and observation.
- Diet (e.g. ad libitum): Pelleted rodent maintenance diet ad libitum, except for the overnight fasting period
- Water (e.g. ad libitum): Community tap water ad libitum
- Acclimation period: At least 5 days under laboratory conditions, after health examination

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 55 and 200 mg/mL
- Amount of vehicle (if gavage):
94.5 mg/kg CMC (55 mg/mL preparation)
80 mg/kg CMC (200 mg/mL preparation)
Calculation: amount CMC in 10 mL preparation= 1% · (10000 mg preparation - x mg substance per 10000 mg preparation), where x is 550 and 2000 mg, respectively
- Justification for choice of vehicle: The vehicle was chosen after non-GLP solubility testing. Purified water and 0.5% CMC in purified water were found unsuitable vehicles for oral gavage application, as the test item could not be sufficiently dispersed in either vehicle. By grinding the test item in a mortar and pestle together with 1% CMC in purified water, a 20% (weight:weight) dispersion of the test item suitable for oral gavage application was obtained.
- Lot/batch no. (if required): 0001414646
- Purity: not reported

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

DOSAGE PREPARATION (if unusual): Dose formulations were prepared shortly before each treatment using a magnetic stirrer and a spatula as homogenizers. The test item was weighed on a suitable precision balance and supplied to a mortar. By using a pestle, the test item and almost all of the vehicle was ground to a dispersion. This dispersion was transferred to a volumetric beaker and the vehicle was added up to the defined volume (weight:volume). Homogeneity of the test item in the vehicle was maintained during administration using a magnetic stirrer.

Doses:

550 mg/kg bw and 2000 mg/kg bw

No. of animals per sex per dose:

1 female with 550 mg/kg bw
3 females with 2000 mg/kg bw

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were examined daily during acclimatization and mortality and clinical signs were assessed. All animals were examined for clinical signs before treatment, once within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on test day 1 and once daily during test days 2 to 15. Mortality was assessed before treatment, once within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on test day 1 (with the clinical signs) and twice daily during test days 2 to 15. Body weights were recorded on the last day of acclimatization (prior to removal of food), on test day 1 (prior to treatment) and on test days 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: mortality, clinical signs, body weight, macroscopy

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths occurred during the course of the study.

Clinical signs:

One animal treated with 550 mg/kg (animal no. 1) and two of the three animals treated with 2000 mg/kg (animals no. 2 and no. 4) showed ruffled fur after treatment on test day 1. In one animal treated with 2000 mg/kg (animal no. 2), ruffled fur was still observed on test day 2. No clinical signs were observed in any animal during acclimatization and from test day 2 until the end of the observation period.

Body weight:

The body weights were within the range commonly recorded for this strain and age.

Gross pathology:

No macroscopic findings were recorded at necropsy.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The median lethal dose (LD50) of the test item after single oral administration to female rats, observed over a period of 14 days, is >2000 mg/kg body weight. The study is considered to be adequate and reliable.

Executive summary:

An acute oral toxicity test with 4 animals (female RccHan:WIST(SPF) rat) was conducted under GLP according to OECD TG 425.

The animals were treated with the test item by gavage at doses of 550 and 2000 mg/kg body weight. Dosing started in one female animal at a dose level of 550 mg/kg. As no death occurred and no severe clinical signs were observed at this dose level, the next female was treated at a dose level of 2000 mg/kg. Two more females were treated at a dose level of 2000 mg/kg, as at this dose no deaths occurred and no severe clinical signs were observed.

All animals were examined for clinical signs before treatment, once within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on test day 1 and once daily during test days 2 to 15. Mortality was assessed before treatment, once within the first

30 minutes and approximately 1, 2, 3 and 5 hours after treatment on test day 1 (with the clinical signs) and twice daily during test days 2 to 15. Body weights were recorded on the last day of acclimatization (prior to removal of food), on test day 1 (prior to treatment) and

on test days 8 and 15. All animals were examined macroscopically after being sacrificed at the end of the observation period.

No deaths occurred during the course of the study. The animal treated with 550 mg/kg and two of the three animals treated with 2000 mg/kg showed ruffled fur after treatment on test day 1. In one animal treated with 2000 mg/kg, ruffled fur was still observed on test day 2. No clinical signs were observed in any animal during acclimatization and from test day 2 until the end of the observation period. The body weights were within the range commonly recorded for this strain and age. No macroscopic findings were recorded at necropsy.

The median lethal dose (LD50) of the test item after single oral administration to female rats, observed over a period of 14 days, is >2000 mg/kg body weight.