AntacidsMagnesium HydroxideAluminum HydroxideSimethiconeMagnesium OxideSilicic AcidCalcium CarbonateHeartburnHistamine H2 AntagonistsRanitidineDrug CombinationsSodium BicarbonateCimetidineSiliconesEsophagitis, PepticDrug InteractionsDuodenoscopyFood-Drug InteractionsGastric Acidity DeterminationTechnetium Tc 99m PyrophosphateBiological AvailabilityFamotidineDosage FormsAnti-Ulcer AgentsSucralfateCarbonatesAlginatesDimethylpolysiloxanesEnoxacinGastroesophageal RefluxGastric AcidPneumonia, AspirationCross-Over Studies