System for controlled release of active agents

摘要

A system for the controlled release of active agents is claimed comprising a core contg. at least one soluble active agent and adjuvants and a shell comprising a film former and a soluble, hydrophilic or hydrophobic plasticiser. The core contains at least one osmotically active substance (I) and at least one polymeric adjuvant (II) capable of swelling. The adjuvant has a less pronounced tendency to hydrate than the active agents and (I). The shell is composed of a permeable or semipermeable wall-forming material. (I) may be e.g. lactose, fructose, dextrose, sucrose, mannitol, NaCl, KCl, K2SO4, mono-, di- or trisodium phosphate. (II) may be e.g. polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose or CMC. The shell may be formed from e.g. cellulose acetate, ethyl cellulose, polyvinyl acetate or a polyacrylic acid copolymer.