Patent ID: 8907100

Claim:
A process for purifying a lansoprazole compound comprises the following steps: step 1) applying a crude lansoprazole material onto an adsorption resin column, which is eluted with an eluent, and collecting the eluate that containing lansoprazole; step 2) adding a half or more of the eluate from step 1) into a crystallization vessel, and concentrating the eluate under a negative pressure and at an elevated system temperature; step 3) decreasing the temperature and seeding a lansoprazole crystal; step 4) maintaining the mixtures at a boiling and concentrated state when fine crystal grains appear, and adding the remaining eluate from the step 1) into the crystallization vessel while stabilizing the temperature for further crystallization to obtain a precipitate; and optionally adjusting the temperature for better crystallization; step 5) separating, washing and drying the precipitate to yield a pure lansoprazole.