Pharmacokinetics of valpromide after oral administration of a solution and a tablet to healthy volunteers

The pharmacokinetics of valpromide, a primary amide of valproic acid, was investigated in 6 healthy, adult male volunteers, each of whom was given 900 mg as a marketed, enteric-coated tablet and a solution. Valpromide was biotransformed to valproic acid after the administration of the tablet and the solution with a bioavailability of 0.79±0.24 and 0.77±0.12, respectively, relative to a marketed tablet of valproic acid. The absorption of valpromide was not rate-limited by dissolution. As a solid, non-hygroscopic, neutral prodrug of valproic acid, valpromide may be a good alternative to valproic acid and sodium valproate.