(558c) Formation Mechanism and Phase Transformation Behaviors of Polymorphs of Esomeprazole Sodium

Esomeprazole sodium is one kind of proton pump inhibitors. In literature, several polymorphic forms of esomeprazole sodium have been reported. However, no detailed information about the stability, formation mechanism and transformation behaviors of esomeprazole sodium has been reported. In this work, Powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Raman spectroscopy, and infrared spectroscopy (IR) were used to identify and characterize different polymorphs of esomeprazole sodium. Single crystal structure of form P was determined. The formation mechanism of form P was investigated and discussed from the molecular level. Presently, form J of esomeprazole sodium is the main commercial product in the market. However, it was found that form J can transform into form P and form L through solvent-mediated transformation and suspension transformation, respectively. Furthermore, selected area electron diffraction (SAED) was used to analysis the structure of different polymorphs of esomeprazole sodium.