Claims for Patent: 5,082,668

Summary for Patent: 5,082,668

Title:	Controlled-release system with constant pushing source
Abstract:	A device is disclosed comprising a wall that surrounds a compartment. The compartment comprises a beneficial agent composition and a push composition. A passageway in the wall connects the compartment with the exterior of the device for delivering the beneficial agent at a rate governed, in combination, by the wall, the beneficial agent composition and the push composition through the passageway of the device over time.
Inventor(s):	Wong; Patrick S. L. (Palo Alto, CA), Barclay; Brian L. (Sunnyvale, CA), Deters; Joseph C. (Los Altos, CA), Theeuwes; Felix (Los Altos, CA)
Assignee:	Alza Corporation (Palo Alto, CA)
Application Number:	07/595,140
Patent Claims:	1. An improvement in a device for delivering a beneficial agent composition to a fluid environment of use, wherein the device comprises: (a) a wall comprising a composition that is permeable to the passage of fluid and is substantially impermeable to the passage of agent, which wall surrounds and forms; (b) a compartment, and wherein the improvement comprises; (c) a beneficial agent composition comprising a beneficial agent and 10% to 90% of an osmopolymer in the compartment, which beneficial agent composition is delivered substantially as a ribbon, at a rate expressed by ##EQU41## is the does of beneficial agent delivered in unit time, ##EQU42## is the total volume of the agent composition delivered in unit time, and C.sub.D is the amount of beneficial agent mixed with the osmopolymer composition delivered from the device; (d) a push composition in contact with the beneficial agent composition in the compartment, which push composition, in the presence of fluid that enters the device, increases in dimension and pushes the beneficial agent composition from the device; and, (e) exit means in the wall for delivering the beneficial agent composition from the device, at a controlled rate over time. 2. An improvement i a device for delivering a beneficial agent to a fluid environment of use, wherein the device comprises: (a) a wall comprising a composition that is permeable to the passage of fluid and is substantially impermeable to the passage of agent, which wall surrounds and defines; (b) a compartment, and wherein the improvement comprises; (c) a beneficial agent composition in the compartment comprising 10% to 90% of an osmopolymer and an osmagent that exhibit fluid influx, which beneficial agent composition is delivered substantially as a ribbon, and when the device is in operation in a fluid environment, a fluid influx ##EQU43## wherein dV is the volume influxed in unit time dt; (d) a push composition in contact with the beneficial agent composition in the compartment, said push composition exhibiting, when the device is in operation, a fluid influx ##EQU44## wherein dV is the volume influxed in unit time dt; and, (e) at least one exit orifice in the wall for delivering the beneficial agent by the cooperating operation of beneficial agent composition and the push composition acting together for delivering the beneficial agent through said orifice. 3. An improvement in a device for delivering a beneficial agent to a fluid environment of use, wherein the device comprises: (a) a wall comprising a composition that is permeable to the passage of fluid and is substantially impermeable to the passage of agent, which wall surrounds; (b) a compartment, and wherein the improvement comprises: (c) a beneficial agent composition in the compartment that is delivered substantially as a ribbon, which composition comprises 10% to 90% of means for absorbing fluid that enters the compartment at a rate ##EQU45## for providing at least a fraction of the composition comprising fluid in unit time dt; (d) a push composition in contact with the beneficial agent composition in the compartment, which push composition absorbs fluid that enters the compartment at a rate ##EQU46## for providing at least in part a fraction of the push needed for pushing the beneficial agent compoition from the device at a rate comprising ##EQU47## wherein F.sub.D is the fraction of beneficial agent in the agent composition and .rho..sub.dc is the density of the beneficial agent composition; and, (e) at least one exit pore passageway in the wall for delivering the beneficial agent composition from the device, at a rate governed by the wall, the beneficial agent composition and the push composition interacting to deliver the beneficial agent through the orifice.