Formation Mechanism and Phase Transformation Behaviors of Pantoprazole Sodium Heterosolvate

In this paper, one new heterosolvate
of pantoprazole sodium (PPS)
was found, and its crystal structure was determined for the first
time. It was found that both water molecules and acetone molecules
get involved in the formation of crystal lattice of pantoprazole sodium
heterosolvate. Powder X-ray diffraction (PXRD), thermogravimetric
analysis (TGA), differential scanning calorimetry (DSC), Raman spectroscopy,
and infrared spectroscopy (IR) were used to identify and characterize
PPS heterosolvate. The phase transformation behaviors between PPS
monohydrate and PPS heterosolvate were also investigated. It was found
that PPS monohydrate can transform into PPS heterosolvate through
either vapor sorption or solvent-mediated transformation. PPS heterosolvate
can also transform into PPS monohydrate in the presence of hexane
vapor or upon heating. Furthermore, the kinetics and mechanisms of
desolvation of PPS heterosolvate were systematically investigated.