Polymorphism: The Phenomenon Affecting the Performance of Drugs

Abstract

Polymorphism is the ability of solid materials to exist in two or more crystalline forms with different arrangements or conformations of the constituents in the crystal lattice. These polymorphic forms of a drug differ in the physicochemical properties like dissolution and solubility, chemical and physical stability, flowability and hygroscopicity. These forms also differ in various important drug outcomes like drug efficacy, bioavailability, and even toxicity. Polymorphic studies are important as a particular polymorph can be responsible for a particular property which might not be exhibited by any other form. This review will discuss the applied nature of polymorphism starting from their preparation, characterization and pharmaceutical importance with a special emphasis on drugs.