Crystallization and transformation of pharmaceutical solid forms

In the past decades, a great progress has been made in the discovery, identification and control of various solid forms of active pharmaceutical ingredients (APIs), including polymorphs, solvates, hydrates, co-crystals, salts and amorphous solids. It is expected that new solid forms with novel properties of pharmaceutical molecules will explosively expand with further understanding of the formation mechanisms of different solid forms. This mini-review briefly introduces the concept, crystallization, characterization, transformation and controlling of various pharmaceutical solid forms by use of exampling some cases.