A PROCESS FOR THE MANUFACTURE OF DIVALPROEX SODIUM

摘要

A process comprising addition of powdered sodium source like (Na)nX wherein X represents OH, OCH3, OC2H5, CO₃, HCO₃, or valproate, in solid form, and n is 1 or 2 to valproic acid at 10-60 °C, and then adding organic solvents or a mixture thereof to obtain a clear solution, followed by cooling to 5-20 °C and isolating the title compound by conventional methods. A still another option, is heating equimolar mixture of Sodium valproate and valproic acid in acetonitrile at 60-75 °C to provide a clear solution, which is then optionally filtered to remove the suspended particles and then slowly cooled to 10-30 °C and filtered and washed with acetonitrile and dried to obtain Divalproex sodium as a snow white powder in above 95 % yield.