SOLUBILITY ENHANCEMENT BY SOLID DISPERSION METHOD: A REVIEW

Abstract

Solid dispersions have attracted considerable interest as an efficient means of improving the dissolution rate and hence bioavailability of a range of hydrotrophic drugs.  Up to 40% of new chemical entities discovered by the pharmaceutical industry today are poorly soluble or lipophilic compounds. Solid dispersions of poorly water-soluble drugs with water-soluble carriers reduce the incidence of these problems and enhanced dissolution. Solid dispersion is one of the most promising approaches for solubility enhancement. The term solid dispersion refers to a group of solid products consisting of at least two different components, generally a hydrophilic matrix and a hydrophobic drug. The matrix can be either crystalline or amorphous. As per biopharmaceutical classification system class II drugs are with low solubility and high permeability and are the promising candidates for improvement of bioavailability by solid dispersion. Some of the practical aspects to be considered for the preparation of solid dispersions, such as selection of carrier, molecular arrangement of drugs in solid dispersions are discussed in this article. This article reviews the various preparation techniques for solid dispersion, characterization and compiles some of the recent technology transfers. Availability of a wide variety of polymers that are themselves poorly soluble or which swell under aqueous conditions suggests that solid dispersions have tremendous potential in the area of controlled release dosage forms.

Keywords: Solid dispersions, solubility, carrier, Biopharmaceutical classification system