PHARMACOLOGY

 BIOASSAY OF INSULIN ::

STANDARD PREPARATION AND UNIT ::

It is a pure dry and crystalline insulin one unit contains 0.04082 mg This unit is specified by ministry of Health Government of India and is equivalent to international unit 

Preparation of standard solution ::

Accurately weigh 20 units of insulin and dissolve it in normal saline Acidify it with HCl to pH 2.5 Add 0.5% phenol as preservative Add 1.4% to 1.8% glycerin Final volume should contain 20 units/ml Store the solution in a cool place and use it within six months 

Preparation of test sample solution :;

The solution of the test sample is prepared in the same way as the standard solution described above 

Methods of bioassay ::

There are two methods : 1. Rabbit method and 2.Mouse method 

1.Rabbit method :: Selection of rabbits ::

They should be healthy weighing about 1800-3000 gms They should then be maintained on uniform diet but are fasted for 18 hrs before assay Water is withdrawn during the experiment 

Standard and Sample dilutions :: 

These are freshly prepared by diluting with normal NaCI solution so as to contain 1 unit /ml and 2 units /ml 

Dose :: 

The dose which can produce suitable fall in blood sugar level is calculated for the standard 

Principle ::

The potency of a test sample is estimated by comparing the hypoglycemic effect of the sample with that of the std preparation of insulin Any other suitable method can also be used