초록 ▼

A self-powered device is disclosed for delivering a useful agent. The device comprises (1) a housing member, (2) a variable volume chamber storing a useful agent and having a passageway for delivering the agent in the housing, and (3) a pressure generating member comprising a semipermeable polymer h

A self-powered device is disclosed for delivering a useful agent. The device comprises (1) a housing member, (2) a variable volume chamber storing a useful agent and having a passageway for delivering the agent in the housing, and (3) a pressure generating member comprising a semipermeable polymer having a cross-linked hydrophilic polymer dispersed therein positioned between the housing and the chamber. In operation, when the device is in a fluid environment, fluid from the environment enters the housing and is imbibed by the hydrophilic polymer into the generator, causing the generator to enlarge and apply pressure against the chamber, thereby decreasing the volume of the chamber and simultaneously dispensing agent through the passageway from the device at a controlled rate over a prolonged period of time. An article of manufacture also is disclosed which consists of a pressure generating member manufactured as a film useful for making a dispensing device.

대표청구항 ▼

A device for delivering a useful agent to an environment of use, comprising: (a) a useful agent; (b) a housing having a shape retaining wall defining an internal space, the housing having at least one opening connecting the space with the exterior of the device; (c) a variable volume chamber in the

A device for delivering a useful agent to an environment of use, comprising: (a) a useful agent; (b) a housing having a shape retaining wall defining an internal space, the housing having at least one opening connecting the space with the exterior of the device; (c) a variable volume chamber in the housing, said chamber comprising a flexible wall surrounding a reservoir for storing the agent, and a passageway for delivering the agent from the chamber to the exterior of the device; (d) a pressure generating member in the housing positioned between the housing and the chamber, said member formed of a semipermeable polymer having therein a swellable, insoluble hydrophilic polymer; and, (e) wherein, in operation when the device is in the environment of use, the member imbibes fluid admitted into the device, causing the member to expand, generate and exert pressure on the chamber which decreases the volume of the chamber thereby delivering agent through the passageway from the device at a controlled rate over a prolonged period of time.