Patent 7638634 was granted and assigned to Hetero Drugs Limited on December, 2009 by the United States Patent and Trademark Office.
The present invention relates to a novel amorphous form of esomeprazole hydrate, to a process for its preparation and to a pharmaceutical composition containing it. Thus, tetrahydrofuran and water are added to esomeprazole potassium salt at 25-30° C., cooled to 20° C. and then the pH is adjusted to 7.5-8.0 with acetic acid. The reaction mass is cooled to 5° C., stirred for 2 to 3 hours at 0-5° C., filtered the mass, washed with chilled mixture of water and tetrahydrofuran (2:1) and again washed with water. The wet cake is dried at 30-35° C. under vacuum to reach the moisture content to 25-30%. The solid is again dried in rotovapour at 25-30° C. under nitrogen atmosphere to give amorphous esomeprazole hydrate.