Pharmaceutical Cocrystals: An Overview

In the last few years, a large number of drugs have been discovered with low aqueous solubility. Among these recently discovered drugs, about 60-70% of the compounds are related to the BCS Class II (low solubility/high permeability) and IV (low solubility/ low permeability)[1,2]. Many active pharmaceutical ingredients (APIs) have not been developed in formulations due to low aqueous solubility, which causes low bioavailability of drugs[3]. The gastrointestinal tract has different pH in different parts, so drugs when given by oral route have different solubility in gastrointestinal fluids at different pH, often leading to nonlinear and variable absorption and efficacy and safety of drugs cannot be evaluated properly. That is why limited solubility of drugs is a major challenge in development of oral dosage forms[4].