Membrane modulated dissolution of oral drug delivery systems

A kinetic model analogous to two chemical reactions occurring in series describes the dissolution behavior of tablets and pellets coated with either microporous or semipermeable membranes. Microporous membranes permit free water influx, but moderated core dissolution and dialytically controlled solution efflux. Semipermeable membranes allow osmotically limited water influx, moderated core dissolution, but relatively unimpeded solution efflux through a release orifice. An explanation is offered which illustrates why the systems perform similarly despite major differences in the membrane structure and need for a release orifice. Applications to literature examples and experimental evidence demonstrate the suitability of the model.