Digoxin is a widely used,
poorly water-soluble cardiac glycoside with a narrow therapeutic index. There is a substantial variation in absolute bioavailability. However, the precise mechanism responsible for the variability has not been fully elucidated. Because of its lipophilicity and apparent linear absorption over a wide concentration range from the same dosage form, digoxin has long been assumed to be absorbed across apical membrane of enterocytes by passive
diffusion. Studies using the rat intestinal BBMV and in vitro Ussing chamber methods suggest the involvement of multiple transport mechanisms (both uptake and efflux
transporters) for digoxin absorption. The influence of two…
