Recent advances in drug polymorphs: Aspects of pharmaceutical properties and selective crystallization.

Drug polymorphism, an established term used to describe the phenomenon that a drug can exist in different crystalline phases, has attracted great interests in pharmaceutical field in consideration of its important role in affecting the pharmaceutical performance of oral formulations. This paper presents an overview of recent advances in the research on polymorphic drug systems including understandings on nucleation, crystal growth, dissolution, mechanical properties, polymorphic transformation, etc. Moreover, new strategies and mechanisms in the control of polymorphic forms are also highlighted in this review. Furthermore, challenges and trends in the development of polymorphic drugs are briefly discussed, aiming at developing effective and efficient pharmaceutical formulations containing the polymorphic drugs.