Tegoprazan (CJ-12420), a potassium-competitive acid blocker, is a potent, oral active and highly selective inhibitor of gastric H+/K+-ATPase that could control gastric acid secretion and motility, with IC50 values ranging from 0.29-0.52 μM for porcine, canine, and human H+/K+-ATPases in vitro.IC50 & Target:IC50: 0.29-0.52 μM (H+/K+-ATPase).In Vitro:Tegoprazan inhibits porcine, canine, and human H+/K+-ATPase activity. Tegoprazan inhibits gastric H+/K+-ATPase in a potassium-competitive and reversible manner. Tegoprazan (3 μM) inhibits 86% of H+/K+-ATPase activity, whereas the inhibition is decreased to 34% after the dilution of Tegoprazan concentration to 0.15 μM.In Vivo:Tegoprazan (1.0 mg/kg, p.o.) potently and completely inhibits histamine-induced gastric acid secretion in dogs. Tegoprazan (1.0-3.0 mg/kg, p.o.) reverses the pentagastrin-induced acidified gastric pH to the neutral range. Tegoprazan (3 mg/kg, p.o.) immediately evokes a gastric phase III contraction of the migrating motor complex in pentagastrin-treated dogs.