PHARMACOLOGY

BIOASSAY OF ADRENALINE 

PRINCIPLE ::

Potency of the test sample is estimated by comparing the rise in blood pressure of the test sample with the produced by the standard preparation of adrenaline 

Standard Preparation ::

It should fulfill all the tests of purity as per adrenaline monograph in the Indian Pharmacopoeia The specific rotation of 4% w/v solution of the standard adrenaline in 0.1 N HCI should lie between -5 .C to 5. C dilutions of adrenaline are prepared by diluting it with saline Suitable concentrations is 1: 10000

Test sample solution is also prepared in saline 

Method Using Anaesthetised Dog ::

A medium size dog (10-13 kg ) is anaesthetised with pentobarbitone sodium in a dose of 25 mg /kg i.v. Artificial respiration is given through tracheal tube if necessary BP is recorded on a kymograph after cannulating carotid artery with arterial cannula and connecting the same with a mercury manometer 

    The animal should be given 0.001-0.002 mg of atropine sulphate to paralyse the vagi This paralysis is confirmed by stimulating vagi by electrical stimulation There will be no fall in BP in atropinised animal after electrical stimulation 

    Adrenaline is injected into the femoral vein through venous cannula Two successive responses of the same dose of adrenaline are noted The similar responses after the same doses of adrenaline is an indication that there is no variation in BP. and that the animal is now ready for the assay Then the test and the standard samples are given in alternate till both produce similar rise in BP Injections are given at intervals of five minutes Potency of the test sample is compared with that of the standard sample 

On Spinal Cat ::

Refer pressor activity of posterior pitutary extract and apply the same method