Polymorphic transformation of L-Serine in water

Abstract

Control and optimization of the polymorph formation require kinetic understandings during polymorph transformation. In this study, two different process analytical tools (PAT), including focused beam reflectance measurement (FBRM) and particle vision measurement (PVM), were applied to monitor the transformation between hydrate and anhydrate of L-Serine and the growth of the hydrous form. Combining the different in situ data, it was clearly observed that temperature increase promotes the transformation rate. Furthermore in transformation from anhydrate to hydrate, dissolution rate of anhydrate decreases with temperature while growth rate of hydrate increases. Finally, given that the overall transformation rate increases with temperature, the transformation mechanism from anhydrate to hydrate was clarified that the nucleation and growth of hydrate is the rate controlling step. FBRM and PVM proved to be efficient tools for monitoring polymorphic transformation online.