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

Abstract 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.