AntacidsMagnesium HydroxideAluminum HydroxideAbsorptionIntestinal AbsorptionSimethiconeMagnesium OxideCalcium CarbonateSilicic AcidBiological AvailabilityHeartburnDrug CombinationsHistamine H2 AntagonistsRanitidineSodium BicarbonateCimetidineDrug InteractionsSiliconesFood-Drug InteractionsAdministration, OralEsophagitis, PepticGastric Acidity DeterminationDuodenoscopyCross-Over StudiesTechnetium Tc 99m PyrophosphateSkin AbsorptionDosage FormsFamotidineHydrogen-Ion ConcentrationAnti-Ulcer AgentsSucralfateCarbonatesAlginatesDimethylpolysiloxanesGastric AcidEnoxacinAluminumGastroesophageal RefluxSpectrophotometry, AtomicX-Ray Absorption SpectroscopyJejunumPneumonia, Aspiration