Pharmaceutical Cocrystals: Design, Development and Characterization

The poor aqueous solubility and dissolution rate of API is one of the main challenge in pharmaceutical development. The improvement of solubility and dissolution profiles of these lipophilic drug molecules without altering the molecular structure is a particular challenge for the successful development of pharmaceutical products. Pharmaceutical cocrystals are molecular complexes of an API and one or more cocrystal formers, which are solids at room temperature, interacting through hydrogen bonding, π-stacking or van der Waals forces. A crystalline form of the API is strongly preferred because of their relative ease of isolation, and the physico-chemical stability that the crystalline solid state affords. The vast majority of APIs occur as solids; these include, salts, polymorphs, cocrystals and hydrates/solvates. Cocrystallization as a method of obtaining new forms of Active Pharmaceutical Ingredients (APIs) with improved physicochemical properties like solubility, stability, and melting point has gained much attention in recent years and is a promising alternative to so far employed preparation of salts, hydrates, solvates and other forms. Cocrystallization improves physicochemical properties of drug without affecting their pharmacological properties. There are various methods for preparation of cocrystals like solvent evaporation, solution crystallization, antisolvent addition, kneading etc. The characterization methods includes FTIR, DSC, PXRD, NMR, Raman spectroscopy etc.