Pharmacokinetic and Bioequivalent Study of Potassium Chloride Sustained‐Release Tablet Under Different Dietary Conditions in Healthy Chinese Subjects

Potassium (K+ ) is an endogenous substance that is an essential dietary component. However, the interaction between dietary arrangements and specific effects of dietary K+ intake in bioequivalence studies remains unclear. To investigate the influence of dietary arrangement on the bioequivalence of potassium chloride (KCl) sustained-release tablets in healthy Chinese volunteers, the pharmacokinetics of KCl were compared in two open-label, single-center, randomized, two-period crossover studies with different dietary conditions. All volunteers received an oral dose of 6 g of KCl sustained-release tablets under fasting conditions, with different dietary arrangements. Urine samples were collected on baseline days and 48 hours after tablet consumption. Inductively coupled plasma-optical emission spectrometry was used to measure the concentration of K+ in the urine samples. Pharmacokinetic parameters were analyzed using Phoenix WinNonlin software in a noncompartmental model. In either clinical trial, no significant differences were observed in the maximal rate of urinary excretion and cumulative urinary excretion from 0 to 24 hours of K+ between the reference and test drugs. The bioequivalence studies of both KCl sustained-release tablet formulations were successfully conducted under different dietary conditions.