Combinatorial chemistry, computational molecular modeling and high throughput screening in drug discovery have significantly increased the number of poorly soluble drugs. About 40% of drugs developed in the past and about 90% of the drugs in development are poorly soluble drugs. When administered orally, a drug has to first dissolve in gastrointestinal fluids before it can be absorbed in to the blood and reach its site of action. The objective of this review article is to outline the key aspects of the commonly used technologies to improve the solubility, dissolution, and bioavailability of poorly soluble drugs. The technologies covered in this article are particle size reduction (micronization and nanosuspensions), solid dispersions (spray drying and hot melt extrusion), lipid based delivery systems, and inclusion complexes. Jet mill and High pressure Homogenizer are used primarily for micronization and preparation of nano suspensions, respectively.

Spray drier and Hot melt extruder are used for the preparation of solid dispersions. The majority of the lipid based formulations are filled into hard or soft gelatin capsules. Drug- cyclodextrin inclusion complexes are generally prepared by Coprecipitate and Spray drying methods. A number of poorly soluble drugs have been successfully introduced to the market by using new technologies. Among the available technologies, solid dispersion formulations and lipid based formulations have shown the most commercial success and continue to be widely employed. Physicochemical characteristics of the drug and advantages and disadvantages of different technologies need in solubility enhancement technologies and sophisticated analytical techniques to measure the performance of the dosage forms in-vitro and in-vivo and new research in the area of modeling and simulation are expected to facilitate the development of new dosage forms that will successfully overcome the limitations of not only poorly soluble drugs but also poorly permeable drugs.

Keywords: Poorly soluble drugs; Micronization; Nanosuspensions; Spray drying