The document describes procedures for acute toxicity tests to determine the lethal dose of a compound. Acute toxicity tests involve administering a single dose of a compound to test animals and observing symptoms and lethality. The LD50 is the dose that causes death in 50% of animals. Tests are done by injection or oral routes in rats or mice. Animals are observed for symptoms and mortality rates over a period of time to determine the LD50 and establish a dose-response curve for lethality. The tests provide information on the lethal concentration and time of exposure, as well as the order of toxicity and symptoms caused by a compound.

2. The test consist of administering the compound on the one
occasion
Purpose
 Deamination the symptomatology consequent
 Determination the order of lethality of the
compound
ACUTE TOXICITY TESTS

3. Some definitions
LD50 : Amount of compound causes the death of 50% of
test animals.
The lower the LD-50, the more toxic the substance.
LCT50: Lethal concentration time that refer the
concentration of the test agent to be killed 50 percent of
the animal when exposure is for 4 hours

4. Route of administration
 Injection
 Oral
Test species : Rat or Mice
 All test animal should be in a state of good health and
should be observed for a period .
 One week for rats and mice and three to four weeks
for dogs

5. The sequence for acute toxicity test
Firstly, An initial rough dose –range finding experiment ,
experiment to narrow the range of effective doses.
Finally, establishing dose – response curve for lethality

6. The initial rough dose-range-finding experiment
 Based on suspected toxicity obtaining from a
knowledge of the structure of the compound .
 Only two Rats or mice are used for each dose.
 By using logarithms of the dose, a range of doses is
experimentally determined that will produce death
versus no effect or minimal effects.
 The animals are observed for a minimum of 24 hr.

7.  A second series of tests then is performed on the
same species using 4 animals in each test group
in an attempt to narrow the range of doses
When the data from dose-range-finding experiment
are obtained, the final experiment is performed.

8. No. of animal : 10 , same sex or both sexes .
Doses : Different dose to produce between 10 and 90%
mortality.
The LD50 is statistically determined
Establishing dose – response curve for lethality

9.  The LCT50 (lethal concentration time) is
determined.
 During the test, the duration of exposure is
always kept constant.
ACUTE TOXICITY TESTS VIA INHALATION

10. Effects observed during experimental determination of
the acute toxicity studies
Activity
Bizarre reaction
Phonation
Sensitivity to pain
Sensitivity to sound
Sensitivity to touch
Social interaction
Abnormal tail
Aggressive behavior
Ataxia
Convulsions
Muscle Tone
Paralysis
Somatic response
Postural Response
Tremors
 Urination
 salivation
 Cardiac

11. Though acute test the following information is found
o At the dose when no activity is observed .
o At the dose when maximum activity is observed .
o At the dose when minimum activity is observed .
o We can also determine the of action .