OSMOTICALLY DRIVEN DISPENSER HAVING A COMPOSITE WALL

摘要

This application discloses an osmotically driven dispenser for dispensing an active agent to a liquid containing environment that has improved resistance to degradation by the active agent. The dispenser comprises: a wall that is permeable to the liquid in the environment and defines a compartment; an active agent composition contained within the compartment that is osmotically effective relative to said liquid and to which the wall is substantially impermeable; and an outlet passageway in the wall through which the active agent composition is dispensed to the environment. The wall is formed of a composite blend of (1) a wall-forming material that is permeable to the liquid and substantially impermeable to the active agent composition and (2) a stabilizer material that makes the blend resistant to degradation by the active agent composition. Optionally, the blend may also contain a plasticizer, a liquid flux enhancer and/or a dispersant.