bis(diethylamino)-N,N-diethylmethaniminium chloride

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD 425 (2001) and US EPA OPPTS 870.1100 (2002); GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Remarks:

OECD GLP

Test type:

up-and-down procedure

Limit test:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test animals

Species:

rat

Strain:

other: Outbred Albino (Rattus norvegicus)

Sex:

female

Details on test animals or test system and environmental conditions:

Eight female outbred albino rats were received from Harlan, Inc. Indianapolis, IN. They weighed 239.2-279.1 g and were at least 49 days old. They were single housed upon arrival in polycarbonate cages with hardwood chip bedding. The animals were acclimated for at least 5 days prior to dosing. Tap water was provided ad libitum throughout the study and feed was provided ad libitum, with the exception of overnight prior to dosing. The temperature and humidity were maintained at 68±5°F and 30-70%, respectively. Room lights were on a 12-hour light/dark cycle.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

The test substance was a liquid and was dosed as provided by the Sponsor. No other preparation was necessary.

Doses:

175, 550 and 2000 mg a.i./kg

No. of animals per sex per dose:

8 females

Control animals:

no

Details on study design:

Food was withheld from the animals the night prior to dosing. Animals were administered a single dose of the test substance by oral gavage. After dosing, the animals were returned to their cages and supplied with feed and water ad libitum.

The first animal was dosed at 175 mg a.i. /kg as the Sponsor indicated that the test substance may have an LD50 of 300 mg/kg. Single animals were dosed sequentially at 48-hour intervals. The interval between dosing was determined by the onset, duration and severity of toxic signs.

The survival of each animal determined if the next animal would receive a higher or lower dose. Dosing continued on the fixed time interval outcome of all the dosed animals. The dosing was terminated when one of the following criteria was met: 1) 3 consecutive animals survived the upper bound; 2) 5 reversals occurred in any 6 consecutive animals tested; or 3) at least 4 animals were dosed following the first reversal and the specified likelihood-ratios exceeded the critical value.

The dose progression factor was chosen as the antilog of 1 (the estimated slope of the dose response curve).

Careful clinical observations were made at least twice daily on the day of dosing. Special attention was given during the first four hours. Animals were observed daily for 14 days for clinical manifestations. Animals were weighed on Day 0, prior to dose administration, Day 7 and Day 14.

Any animal found dead was necropsied as soon as possible, but in no case later than 12 hours. A gross necropsy was performed on all animals whether found dead, euthanized in extremis, or sacrificed at the end of the study.

Any other information on materials and methods, including tables: An evaluation of acute toxicity data included the relationship, if any, between the animals exposed to the test substance and the incidence and severity of all abnormalities, including behavioral and clinical abnormalities, gross lesions, bodyweight changes, effects on mortality, and any other toxic effects. Calculation of the LD50 and the confidence intervals of the test substance were determined by using the maximum likelihood method. A statistical computer program (AOT425StatPgm) developed by the U.S. EPA was used for the calculation.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

550 other: mg a.i./kg

95% CL:

114.7 - 824

Mortality:

Animals dosed at 175 mg a.i./kg survived to study termination. Three of four animals dosed at 550 mg a.i./kg died prior to the end of the study, two at four hours post-dose and one on Day 3. The two animals dosed at 2000 mg a.i./kg were found dead within four hours post-dose.

Clinical signs:

Animals dosed at 175 mg a.i./kg did not exhibit any clinical signs throughout the course of the study. Prior to death, the animal dosed at 550 mg a.i./kg that died on Day 3 was observed with piloerection, severe tremors and cyanosis. The animals dosed at 2000 mg a.i./kg had no reported observations.

Body weight:

Animals dosed at 175 mg a.i./kg gained weight throughout the course of the study. The surviving animal dosed at 550 mg a.i./kg gained weight by the end of the study.

Gross pathology:

No unusual findings were found during necropsy for the animals dying on study or euthanized at study termination.

Applicant's summary and conclusion

Conclusions:

Under the conditions of the study, the test substance was estimated to have an acute oral LD50 of 550 mg a.i./kg with a 95% Confidence Interval of 114.7 to 824 mg a.i./kg.