POORLY SOLUBLE DRUGS- A CHALLENGE IN DRUG DELIVERY SYSTEM

Padmini H. Sharma*, Shweta N. Kalasare, Hardik Damania

ABSTRACT

The therapeutic effectiveness of a drug depends upon the bioavailability and solubility. The process of solubilisation involves the breaking of inter-ionic or inter-molecular bonds in the solute, the separation of the molecules of the solvent to provide space in the solvent, interaction between the solvent and the solute. The various factors affecting solubility are particle size, temperature, pressure, nature of the solute and the solvent, molecular size, polarity, etc. It is estimated that about 40% of compounds being developed by pharmaceutical industry are poorly water soluble which serves serious challenge to the successful development of new drugs. A limiting factor to this is the inadequate dissolution rates. Thus, increasing the dissolution rate of poorly water soluble active pharmaceutical ingredients has become a major challenge and transfers them into highly bioavailable drug delivery systems by distinct measures such as chemical transformation, biopharmaceutical measures and physiological measures. Multiple technologies are available for the successful formulation of poorly soluble drugs such as controlled precipitation, ultra-rapid freezing, hydrotropic solubilisation, complexation, solid dispersion, salt formation, use of co-solvents, solubilzing agents, co-crystallization, etc. Overall, discoveries of new technologies will be useful for drugs with problems of poor solubility and bioavailability, which would allow future drugs and new entities to reach market successfully and thereby, serve mankind in a better way.

Keywords: Solubilisation, Bioavailability, Solubility, Pharmaceutical Industry.