Solid Dispersions: Technique to Enhance Solubility of Poorly Water Soluble Drug

Abstract

Solid dispersions are one of the most promising strategies to enhance solubility of poorly water soluble drugs because they are easier to produce and more applicable. They show many advantages such as reducing particle size of drug, improving wettability and dissolvability, and converting crystalline structure of drug to amorphous form. The solid dispersions can also be classifi ed into three generations based on composition of formulation i.e. fi rst generation (using crystalline carriers: urea, mannitol), second generation (using amorphous carriers: polyvinylpyrrolidone, polyethylene glycol, hydroxypropyl methylcellulose) and third generation (using surfactant or amphiphilic polymer carriers: Gelucire®, Poloxamer®, Soluplus®). There are three different methods to prepare solid dispersions such as melting or fusion method, solvent evaporation method and melting-solvent method. Nowadays, solid dispersions have been developed in manufacturing process to solve the drawback of the initial process such as hot melt extrusion, MeltrexTM, spray dry, freeze dry. Thus, the review article presents an overview of defi nition of solid dispersion, advantages and disadvantages, classifi cation according to generation and type of carrier including preparation and evaluation of solid dispersions.