PROBLEM TO BE SOLVED: To provide a method for preparing a substantially pure lansoprazole containing less than about 0.2% (wt/wt) impurities including sulfone/sulfide derivatives, and also to provide a method for recrystallizing lansoprazole to obtain lansoprazole containing only less than about 0.1% (wt/wt) water. ; SOLUTION: The method includes: providing a solution of lansoprazole in a solvent selected from an organic solvent, or a mixture of an organic solvent and water in the presence of an...

PROBLEM TO BE SOLVED: To provide a stable 2-(2-pyridylmethyl)sulfinyl-lH-benzimidazole (lansoprazole), to provide a method for stabilizing the lansoprazole by use of a weakly basic material, and to provide a method for preparing the stable lansoprazole. ; SOLUTION: The process of preparing the stable lansoprazole comprising the steps of: (a) washing the filter cake containing the lansoprazole with an ammonium hydroxide solution, (b) drying the washed lansoprazole in the presence of at least one ...

PROBLEM TO BE SOLVED: To provide a method for producing a stable lansoprazole, and a preparation composition containing the stable lansoprazole. ; SOLUTION: The stable 2-(2-pyridylmethyl)sulfinyl-lH-benzimidazole (lansoprazole) comprises either greater than 500 ppm and not more than about 3,000 ppm water and greater than 200 ppm and not more than about 5,000 ppm alcohol, or both. ; COPYRIGHT: (C)2007,JPO&INPIT

The present invention provides a method for preparing a substantially pure lansoprazole containing less than about 0.2% (wt/wt) impurities including sulfone/sulfide derivatives. The present invention also provides a process for recrystallizing lansoprazole to obtain a lansoprazole containing less than about 0.1% (wt/wt) water.