Controlled release formulation of divalproex sodium

A oral polymeric controlled release formulation suitable for once-a-day administration comprising:

• a) from about 40 to about 80 w/w % of divalproex sodium
• b) a pharmaceutically acceptable hydrophilic polymer in which said hydrophilic polymer is present in the quantity of from bout 20% to about 50%, by weight of the formulation, and said hydrophilic polymer is selected from the group consisting of polyvinylpyrrolidine, hydroxypropylcellulose, hydroxypropylmethyl cellulose methyl cellulose, vinyl acetate copolymers, polysaccharides, polyethyleneoxide, methacrylic acid copolymers and maleic anhydride/methyl vinyl ether copolymers and;
• c) when said formulation is ingested orally by healthy human-subjects, said formulation produces:
• i. a Cmax that is statistically significantly lower than the Cmax produced by an enteric coated delayed release divalproex sodium tablet given twice daily, when each Cmax is determined at steady state in a fasting population,
• ii. a Cmin that is not statistically significantly different from the Cmin produced by said delayed release divalproex sodium tablet, when each Cmin is determined at steady state in a fasting population, and;
• iii. said formulation produces an AUC value that is equivalent to the AUC value generated by said divalproex sodium delayed release tablet, when each AUC is determine at steady state in a fasting population.