Abstract

STRATEGIES FOR SOLUBILITY ENHANCEMENT

Amrutha O.* and Shijith K. V.

Abstract

The solubility of drug in the biological milieus and its permeability across biological barriers are the two main central attributes that contributes to therapeutic effectiveness of any drugs. The low solubility is related to a lower drug dissolution rate, which in turn directs poor bioavailability. Approximately 40% of the marketed drugs have low solubility and almost 80-90% drug candidates in the R& D product development pipeline fails due to the solubility concerns. Solubility may be defined as the concentration of the solute in concentrated solution at a certain temperature. The process of solubilization involves the breakage of intermolecular or interionic bonds in the solute molecule, the split-up of the solvent component to provide space in the solvent for the solute, and interaction between the solvent and the solute molecule or ion. When the drug is administered orally, it has to first dissolve in the gastrointestinal fluids before it can be absorbed in to the blood and reach its site of action. The objective of this article is to briefly outline the key aspects of the techniques used to improve the solubility, dissolution, and bioavailability of poorly soluble drugs. The techniques used are micronization, solid dispersion, lipid-based delivery system, inclusion complexes, prodrug approach etc. A number of poorly soluble drugs have been successfully introduced to the market by using new technologies. This review focus on the solubilization techniques explored in pharmaceutical product development to enhance aqueous solubility.

Keywords: Solubility, cyclodextrins, solid lipid nanoparticles, biopharmaceutical classification system, self -microemulsifying drug delivery system, self-nanoemulsifying drug delivery system, solid dispersion.