초록 ▼

A device is disclosed for the controlled delivery of a beneficial agent. The agent is delivered to the environment surrounding the device at a substantially constant rate for a specified period with a reduced dependence on the environmental pH. The device is comprised of a core compartment containin

A device is disclosed for the controlled delivery of a beneficial agent. The agent is delivered to the environment surrounding the device at a substantially constant rate for a specified period with a reduced dependence on the environmental pH. The device is comprised of a core compartment containing (1) a charged, water insoluble, non-diffusible component and (2) at least one diffusable water soluble ionizable beneficial agent. The core is surrounded by a water insoluble wall containing leachable pore forming additive(s) dispersed throughout said wall, with said wall impermeable to core components (1) and permeable to beneficial agent(s) (2). In operation the insoluble charged component (often polymeric resins) and water soluble ionizable beneficial agent have the same electro-static charge and do not form an ion exchange complex. Rather, a Donnan influenced mass transport phenomena of the beneficial agent is effected through the pores in the device, actuated by water from the environment, with migration of the freely mobile diffusible species (beneficial agent) away from the non-mobile species (charged entity). This effects the release of the beneficial agent through the wall at a controlled rate with reduced pH dependency.

대표청구항 ▼

A drug-delivery device for the controlled release of a therapeutically active ingredient into an environment of use which comprises: (A) a core composition comprising (a) a water insoluble, non-diffusible charged resin entity, and (b) a diffusible water soluble ionizable therapeutically active ingre

A drug-delivery device for the controlled release of a therapeutically active ingredient into an environment of use which comprises: (A) a core composition comprising (a) a water insoluble, non-diffusible charged resin entity, and (b) a diffusible water soluble ionizable therapeutically active ingredient carrying the same charge as said resin entity; and (B) a water insoluble wall surrounding said core composition and prepared from (i) a polymer material that is permeable to water but substantially impermeable to solute and (ii) 0.1 to 75% by weight, based on the total weight of (i) and (ii), of at least one water leachable pore forming additive dispersed throughout said wall.