Retard composition for gastrointestinal release of active substance comprises carrier and active substance layers with interposed gastro-insoluble layer

摘要

A retard (depot) composition for the release of active substances in the gastrointestinal tract contains a layer of substance which is insoluble in gastric juice sandwiched between a spongy material which is insoluble in gastrointestinal fluid and/or body fluids and a layer containing active agent. The composition comprises: (a) a spongy expandable material which is insoluble or has poor solubility in gastrointestinal fluid and/or body fluids; (b) a depot layer comprising a formulation containing active substance(s); and (c) one or more binding layers disposed between (a) and (b) and comprising substances which are insoluble or have poor solubility in gastric juice. An Independent claim is also included for the preparation of the composition.