Bioequivalence studies of a new valproic acid delayed-release capsule and divalproex sodium delayed-release tablet.

Objective: The study examined relative bioavailability of a novel valproic acid (VPA) delayed-release (DR) soft gelatin capsule formulation to divalproex sodium DR tablet under fasting conditions and the effect of food on the bioavailability of the VPA DR soft gelatin capsule.

Method: This open-label, randomized three-way crossover study enrolled 36 healthy non-smoking adult volunteers. Treatments included a single 500 mg divalproex sodium DR tablet, fasting; a single 500 mg VPA DR soft gelatin capsule, fasting; and, a single 500 mg VPA DR soft gelatin capsule 500 mg, non-fasting.