title: Absorption kinetics of procainamide in humans.
abstract: Plasma procainamide concentrations following the administration of 500 mg of procainamide hydrochloride via intravenous infusion, conventional capsules, and sustained-release tablets were compared in 11 healthy male volunteers. Two-compartment open modeling of the plasma levels from the intravenous infusion experiments yielded mean Kel, k12, and k21 values of 0.0162, 0.0542, and 0.0233 min-1, respectively. The bioavailability of the oral preparations (versus intravenous) averaged 83% for the capsule and 79% for the sustained-release tablet. Calculations using a previously reported method suggested that absorption was a first-order process with mean ka's of 0.0336 and 0.0039 min-1 for the capsule and sustained-release tablet, respectively. The sustained-release formulation exhibited delayed release and adequate bioavailability.
mesh_terms: D000107:Acetylation; D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D002214:Capsules; D003692:Delayed-Action Preparations; D006801:Humans; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D011342:Procainamide / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D011342:Procainamide