Physical characterization of pantoprazole sodium hydrates

Only two crystal forms of pantoprazole sodium, i.e. mono and sesquihydrate, were described in the literature. The objective of the present work was to study the polymorphisms and pseudopolymorphism of pantoprazole sodium and to characterize already known and new crystal forms. Two additional hydrate forms; i.e. form A, form B and amorphous form were obtained and further characterized by means of thermal analyses, X-ray powder diffraction (XRPD), mid-infrared spectroscopy (IR), near infrared spectroscopy (NIR), Raman spectroscopy, dynamic vapour sorption (DVS), true density, contact angle and solubility. From the results it can be concluded, that the most physically stable form of pantoprazole sodium is form B, whereas form A is the least stable form. Monohydrate and form A are not physically stable and convert into form B from saturated solution/suspension or at high relative humidity. Amorphous form can be obtained by conventional spray drying method or by distillation of solvent under reduced pressure.