OSMOTIC DELIVERY SYSTEM HAVING SPACE EFFICIENT PISTON

摘要

An osmotic delivery system having a space efficient piston. The capsule has an interior holding the piston, a beneficial agent, and an osmotic agent. The piston is movable with respect to an interior surface of the capsule, and defines a movable seal with the interior surface of the capsule. The movable seal separates the osmotic agent from the beneficial agent. The piston has a recess that receives at least a portion of the osmotic agent. The osmotic agent imbibes liquid from a surrounding environment through a semipermeable body to cause the piston to move and in turn cause delivery of the beneficia l agent from the capsule.