AN OVERVIEW ON DIFFERENT APPROACHES FOR SOLUBILITY ENHANCEMENT OF POORLY WATER-SOLUBLE DRUGS

Solubility is one of the major parameter to obtain desired concentration of drug in systemic circulation for pharmacological response to be displayed. Drug efficiency is directly proportional to the solubility of a drug. Poor solubility of a drug leads to low dissolution rate and is followed by low absorption of the drug in the gastro intestinal tract when administered orally. Around 40% of all new chemical entity shows poor bioavailability. Enhancing the bioavailability of poorly soluble drugs can be one of the biggest challenges for formulation scientists in the upcoming years. Molecules that would have highly beneficial effect on their physiological target would not be further developed if their bioavailability is limited by their solubility in water. Aqueous solubility of drug also affects physical, chemical properties of the drug, dose, stability in gastrointestinal track, severs as standard for test of purity, the rate of dissolution of solid, rate and extent of absorption, achieve desired concentration of drug in systemic circulation for desired (anticipated) pharmacological response. Thus solubility is a most important concept presenting itself as valuable contributor in the formulation of pharmaceuticals. The purpose of this review is to discuss the various solubility enhancement technique like chemical modification which includes salt formation, co-crystallization, co-solvency, hydrotrophy, nanotechnology etc and physical modification includes particle size reduction, complexation, surfactants, solid dispersions etc and pH adjustment, supercritical fluid process, liquisolid technique, polymeric alteration. These technologies enhance the solubility of the drugs and thus allows to make the formulations in different dosage forms efficiently and thus enhances the dissolution and bioavailability of the drug.