Bioavailability of orally administered propiram fumarate in humans

Propiram bioavailability was determined in 10 healthy volunteers after a single role administration of 50 mg (base equivalent) of propiram fumarate in tablet or solution dosage from in a randomized crossover design. The plasma drug concentration-time curve revealed a one-compartment open model with first-order absorption kinetics. There were no statistically significant differences (P greater than 0.05) between all of the measured pharmacokinetic parameters obtained from the tablet and the solution with the exception of the absorption lag time (tlag), where the tablet had a significantly longer tlag. The drug given as a tablet or solution was absorbed rapidly after oral administration with an apparent absorption rate constant of 3.7 hr-1 for both dosage forms. The Cmax value (308 ng/ml for the tablet and 342 ng/ml for the solution) was attained at approximately 1 hr after oral administration. The elimination half-life was 5.2 hr for the tablet and 4.4 hr for the solution, and the apparent distribution volume was 2.31 liters/kg for the tablet and 1.94 liters/kg for the solution. Total body clearance was much greater than renal clearance, indicating extensive metabolic clearance for both dosage forms. The study showed that propiram administered as the tablet was bioequivalent to the solution.