Pharmacokinetics and relative bioavailability of modified-release tablets of potassium chloride in healthy volunteers

AIM To establish an ion-selective electrode method to study the pharmacokinetics and relative bioavailability of modified-release tablets of potassium chloride in Chinese healthy volunteers.METHODS Twenty male healthy volunteers received 5.0 g potassium chloride tested tablet or reference tablet orally in a random crossover design. Urinary potassium was determined by ion-selective electrode and the cumulative urine potassium-time data were fitted to a one-compartment model.Bioavailability was represented by cumulative amount of potassium excreted in urine during 48 h after drug administration and the bioequivalence of the two formulations was evaluated by analysis of variance and two one- sided t-test.RESULTS The main pharmacokinetic parameters of tested tablet and reference tablet were as follows: t_(1/2)ke:(9.2±3.0) vs (8.9±3.1) h,t_(1/2)ka:(0.22±0.11) vs (0.21±0.09) h,R_(max):(2.15±0.70) vs (2.21±0.73) mmol·h~(-1).The relative bioavailability of the tested tablet was (98.95±11.5)%.CONCLUSION The results demonstrate that the tested tablet and reference tablet are bioequivalent.