co-crystals

Co-crystallization is an emerging approach for enhancing physicochemical properties like solubility, stability, bioavailability of poorly soluble drugs of BCS class II in pharmaceutical development without changing the chemical composition and considered better alternatives to optimize drug properties. Co-crystal is a crystalline entity consists of API and a stoichiometric amount of a pharmaceutically acceptable co-crystal former formed by intermolecular interactions like Hydrogen bonding, π-π stacking and Van der Waals forces. In this article, an overview of pharmaceutical cocrystals will be presented along with the intermolecular interactions (Chemistry of Co-crystals), methods of their preparations, characterization of co-crystals altered physicochemical properties. Furthermore, this article also gives a brief explanation about newer trends in co-crystals with application of co-crystals in medicines and industries.

Co-crystals consists of API and a stoichiometric amount of a pharmaceutically acceptable co-crystal former. Pharmaceutical Co-crystals are nonionic supramolecular complexes and can be used to address physical property issues such as solubility, stability and bioavailability in pharmaceutical development without changing the chemical composition of the API. Maximum of the drugs belong to BCS class II, means these are drugs which have low solubility and high permeability. There are various methods of solubility enhancement such as salt formation, solvates, polymorphs, complexation, co-crystallization, etc. Co-crystallization mainly consists of two components the API and the coformer. Thse coformer is the one which acts as a main component for solubility enhancement. In case of ionization or salt formation there is a drawback as compared to co-crystallization. In case, of salt formation or ionization presence of an ionic center is required. This is not a requirement in case of co-crystallization.FDA has approved such combination called Juvisync1 (Sitagliptin and Simvastatin) in 2011.Glipizide belongs to the anti-diabetic class of drug and Rosuvastatin calcium is a cholesterol reducing agent. As both these drugs are class II drug, solubility issues has to be solved. As Glipizide was available not in its salt form, its co-crystallization was decided to do. Hence, co-crystallization method was selected as the method to enhance the solubility. The co-crystals were characterized and showed the conformance of the presence of both the APIs.