PHARMACEUTICAL CO-CRYSTALS: A NOVEL APPROACH AND TECHNIQUES FOR SOLUBILITY ENHANCEMENT

Poonam Shankar Nalawade*, Shubhangi Jagannath Patil, Ulka Nathuram Mote, Prachi Prasad Haval, Swati Prakash Gatade and Vishnu Sudhir Phuke

ABSTRACT

Majority of drugs marketed worldwide are administered by oral route. About 40% of the new molecular entities coming from discovery were never brought to the market because of biopharmaceutical issues like low solubility, low dissolution rate, low permeability and first-pass metabolism. There are various methods to improve the dissolution/bioavailability of poorly soluble drugs including Pro-drug approach, Salt synthesis, Particle size reduction, Complexation, Change in physical form, Solid dispersions & Spray drying. Amongst them Salt formation is one of the most frequently used approaches to improve physiochemical properties of moieties which involve formation of ionic bonds. Co-crystallization is a method of formation of mainly hydrogen bond between the drug molecule and co-former so API regardless of acidic, basic, or ionisable groups could potentially be co- crystallized. Co crystallization can improve physiochemical properties like solubility, dissolution rate, chemical stability and melting point. Interactions which are responsible for the formation of co-crystals include hydrogen bonding, π-stacking, and Vander Waals forces. The article gives a brief review on the co-crystallization, their method of synthesis, its importance as an alternative over salt formation, Characterization and applications.

Keywords: Co crystal, Solubility and Bioavailability Aspects, Drug Solubility, Novel Approach.