[Characterization and stability of S (-) pantoprazole sodium hydrates]

Objective: To study the characteristics and stability of new S(-) pantoprazole sodium hydrates. Methods: The X-ray single crystal diffractometer (SXRD), X-ray powder diffractometer (PXRD), thermogravimetric analysis (TG) and infrared spectrometry (IR) were used to characterize S(-) pantoprazole sodium hydrates. The stability of the hydrates was evaluated by high temperature test,affecting factors test and accelerated test. Results: The crystalline water in S(-) pantoprazole sodium hydrates were very easy to lose and obtain, but crystal structure was not changed significantly. The transition from S(-) pantoprazole sodium trihydrate to S(-) pantoprazole sodium hemipentahydrate occurred at approximately 40 ℃ and reversible transitions from hemipentahydrate to trihydrate occurred at high humidity. Two hydrates had no significant difference in accelerated test. Conclusion: The crystal structure of the two hydrates are almost the same, hemipentahydrate is more stable than trihydrates at high temperature or at exposure to light(at 4500 ± 500 lx).