In this study, ER torsemide is tested for within-subject variability in fully replicate design double-crossover trial in healthy volunteers who are on a 300 mmol/day sodium diet (high salt diet). The primary endpoint of the study is full pharmacokinetics measurements after a single dose of either ER torsemide or IR torsemide (Demadex). The secondary endpoints are 24h sodium excretion and total urinary excretion.