OBJECTIVE To investigate the safety, pharmacokinetics and food effect of iptakalim in healthy adult Han Chinese volunteers. METHODS Study 1 was a randomized open-label, Latin square designed, single-dose, three-period, self-control crossover study. Six men and six women received 5, 10 and 20 mg of iptakalim orally. Study 2 was a randomized, open-label, single-dose, two-period, self-control crossover study. Ten men were included and each subject received 5 mg iptakalim orally, fasting and nonfasting. RESULTS No adverse effects were reported and no clinically meaningful changes in vital signs were found. Cmax, AUC(0-t) and AUC(0-∞) were proportional over the dose levels of 5, 10 and 20 mg. Tmax, t½ and CL/F were similarly independent of dose level. In the 5 mg and 20 mg group, the Cmax, AUC(0-t) and AUC(0-∞) in women were significantly higher than in men, although they showed no difference after correction by mg/kg doses in the 5 mg group. At the 5-mg dose level, no significant difference in pharmacokinetics was found in nonfasting and fasting subjects. CONCLUSIONS Single-dose pharmacokinetics of iptakalim showed dose proportionality over the dose levels of 5-20 mg. The pharmacokinetics showed gender differences in the 5 and 20 mg groups. Food had almost no impact on the pharmacokinetics at the 5 mg level.