FORMULATION AND DEVELOPMENT STRATEGIES FOR DRUGS INSOLUBLE IN GASTRIC FLUID

Abstract

A success of formulation depends on how efficiently it makes the drug available at the site of action. Therapeutic effectiveness of a drug depends upon the bioavailability and ultimately upon the solubility of drug molecules especially in the gastric fluid for oral delivery of the drug molecules. But most of the time it becomes challenging to formulate poorly water soluble drugs. Therefore it is necessary to improve solubility of drug by various ways like solid dispersions, hot-melt extrusion, spray freezing into liquid, super critical fluid technology, micellar technology, spray drying, liquisolid technology, salt formation, co- solvency, and addition of solublizing agent, micronization, and complexation. Although these techniques have commonly been used to increase dissolution rate of the drug, there are practical limitations with these techniques, the desired bioavailability enhancement may not always be achieved. One such formulation approach that has been shown to significantly enhance absorption of such drugs is to formulate/prepare solid dispersions. The purpose of this review article is to describe the techniques of solubilizaton for the attainment of effective absorption and improved bioavailability.