Pharmacokinetic study on saturated hepato-biliary transport of acetyl procainamide ethobromide

Pharmacokinetic analysis of plasma concentration of acetyl procainamide ethobromide (APAEB) after single injection of 1.5, 8.8 and 20 mumol/300 g rat of APAEB showed that its elimination from plasma followed saturation kinetics. The existence of saturable step in transport of APAEB from blood to bile was also evident from the data of the biliary excretion at three dose levels. The data of the biliary excretion were well fitted to two compartment model with two saturable processes at the hepatic uptake and the biliary excretion. The Michaelis-Menten parameters were calculated according to that model. The model was also applicable to the data of biliary excretion obtained by constant infusion of APAEB Simulation of liver and plasma content gave a good agreement to the experimental data. All these results indicate that the pharmacokinetics of APAEB is satisfactorily represented by the proposed model.