Relationship between Crystal Form of Cefoperazone Sodium and Its Stability

Objective: The aim of this work was to study the relationship between the crystal form of Cefoperazone sodium (CPZ-Na) and its stability. Methods: To classify CPZ-Na into amorphous powder and crystalline, powder X-ray diffraction (PXRD) was used. To classify CPZ-Na crystal powder into crystal form A and B, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used. To further classify CPZ-Na crystal form A into different subtypes, clustering of PXRD data and scanning electron microscopy (SEM) were used. To compare the stability of CPZ-Na crystal form A and B, temperature controlled PXRD and high performance liquid chromatography (HPLC) were used. Results: CPZ-Na was classified into amorphous powder and crystalline, CPZ-Na crystal powder was classified into crystal form A and B, and CPZ-Na crystal form A was further classified into different subtypes. Moreover, the stability of CPZ-Na crystal form A was higher than that of crystal form B, and different subtypes of CPZ-Na crystal form A had different stability. Conclusions: There was a close relationship between the crystal form of CPZ-Na and its stability.