A Comprehensive Insight on Pharmaceutical Co-crystals for Improvement of Aqueous Solubility

Various drugs are not able to reach the market due to their poor bioavailability and poor solubility in aqueous media. Hence, several approaches are used to enhance the solubility of poorly water-soluble drugs. Co-crystallization is one of the approaches used to enhance the solubility of poorly water-soluble drugs. Co-crystals are solid crystalline substances consisting of two or more ingredients in a stoichiometric ratio in which one of the ingredients is an active pharmaceutical ingredient (API) and the other is a co-former. API and co-former mix with one another in a co-crystal through intermolecular interactions. This review represents an overview of co-crystals, a comparison of co-crystals and other solid forms, mechanisms of solubility enhancement by co-crystals in brief, techniques of co-former selection, a list of co-formers used during various co-crystals formation and a list of marketed co-crystals formulation, method of co-crystals preparation and characterization techniques of co-crystals.