Lansoprazole is a proton-pump inhibitor (PPI) which inhibits the stomach's production of gastric acids. It is manufactured by a number of companies worldwide under several brand names. In the United States, it was first approved by the Food and Drug Administration (FDA) in 1995. Prevacid patent protection expired on November 10, 2009. There is not evidence that its effectiveness is different than that of other PPIs. Lansoprazole is a proton-pump inhibitor (PPI) in the same pharmacologic class as omeprazole. Lansoprazole has been marketed for many years and is one of several PPIs available. It is a racemic 1:1 mixture of the enantiomers dexlansoprazole (Dexilant, formerly named Kapidex) and levolansoprazole. Dexlansoprazole is an enantiomerically pure active ingredient of a commercial drug as a result of the enantiomeric shift. Lansoprazole's plasma elimination half-life (1.5 h) is not proportional to the duration of the drug's effects to the person (i.e. gastric acid suppression). and the effects of the drug last for over 24 hours after it has been used for a day or more. Lansoprazole, given nasogastrically, effectively controls intragastric pH and is an alternative to intravenous pantoprazole in people who are unable to swallow solid-dose formulations.