Increasing Bioavailability of Poorly Water-Soluble Drugs by Their Modification

Abstract

About 40 % of newly developed pharmaceutical compounds are poorly soluble in water. The fact is a challenge to formulation of drug forms with acceptable bioavailability. This is also the reason why more than a half of currently authorized drugs contain salts or other water-soluble derivatives. Preparation of crystals of a drug - adjuvant complex appears to be a promising way of improving drug solubility. Lyophilization and preparation of a more soluble prodrug or a polymorph also afford an opportunity of increasing drug bioavailability. Although micronization (reducing particle size) is the most common method used in pharmaceutical industry, controlled crystallization (sonocrystallization, crystallization in supercritical media and spray drying) is a good alternative. The review presents the most important methods of modification of poorly water-soluble drugs for increasing their solubility and bioavailability, summarizes the main advantages and drawbacks of the methods and gives examples of relevant technological processes.