Patent US5795591A successfully refreshed from Google Patents.
US5795591A
Expired / Lapsed
US
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Osmotic drug delivery devices with hydrophobic wall materials
Assignee: Alza Corp
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Filing: 1994-09-01
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Granted: 1998-08-18
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Expires: 2014-09-01
Abstract
Abstract Osmotically driven drug delivery devices with walls of porous hydrophobic material as the sole diffusion-limiting wall component are disclosed. Despite pores which are considerably larger than the molecular dimensions of osmotically active species in the interior of the device, despite pores which by their hydrophobic character do not permit the passage of liquid water, and despite the absence of a cellulosic semi-permeable membrane, the devices absorb water by osmosis without loss of the osmotically active species, and function in a manner analogous to osmotic pumps of the prior art. By permitting the use of hydrophobic substances as the wall material, the invention permits the device to be constructed entirely from biodegradable materials.
Inventors
- 👤 Eun Soo Lee
- 👤 Scott A. Bura
- 👤 Su Il Yum
- 👤 Patrick S.-L. Wong
- 👤 Felix Theeuwes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:33
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0002; A61K9/0004
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
150 words
An osmotically driven device for lodgment in an aqueous environment in the interior of an animal for the controlled delivery of a beneficial agent to said animal, said device comprising: (a) a beneficial agent; (b) an osmotically active substance which expands on exposure to water in the aqueous environment; and (c) a wall, surrounding said agent and said substance, and defining an exit orifice for releasing said agent therethrough in response to expansion of said substance; said wall being formed of a non-wetting hydrophobic material which material is a biodegradable polymer selected from the group consisting of poly (lactic acid), poly (glycolic acid), and copolymers of lactic acid and glycolic acid, and at least a section of said wall having air-filled interconnected pores therethrough, through which pores water vapor from the aqueous environment passes into the substance, said wall section being impermeable to liquid water and permeable to water vapor.
Claim 2
Dependent Claim
150 words
An osmotically driven device for lodgment in an aqueous environment in the interior of an animal for the controlled delivery of a beneficial agent to said animal, said device comprising: (a) a beneficial agent; (b) an osmotically active substance which expands on exposure to water in the aqueous environment; and (c) a wall, surrounding said agent and said substance, and defining an exit orifice for releasing said agent therethrough in response to expansion of said substance; said wall being formed of a non-wetting hydrophobic material which material is a biodegradable polymer selected from the group consisting of poly (lactic acid), poly (glycolic acid), and copolymers of lactic acid and glycolic acid, and at least a section of said wall having air-filled interconnected pores therethrough, through which pores water vapor from the aqueous environment passes into the substance, said wall section being impermeable to liquid water and permeable to water vapor.
Claim 3
Dependent Claim
22 words
An osmotically driven device in accordance with claim 1 in which said pores are from 0.01 micron to 1000 microns in diameter.
Claim 4
Dependent Claim
22 words
An osmotically driven device in accordance with claim 1 in which said pores are from 0.1 micron to 500 microns in diameter.
Claim 5
Dependent Claim
22 words
An osmotically driven device in accordance with claim 1 in which said pores are from 3 microns to 300 microns in diameter.
Claim 6
Dependent Claim
22 words
An osmotically driven device in accordance with claim 1 in which said pores are from 30 microns to 100 microns in diameter.
Claim 7
Dependent Claim
35 words
An osmotically driven device in accordance with claim 1 in which said osmotically active substance is a material selected from the group consisting of a water-swellable hydrophilic polymer, water-soluble salts, water-soluble saccharides, and combinations thereof.
Claim 8
Dependent Claim
25 words
An osmotically driven device in accordance with claim 1 in which said beneficial agent and said osmotically active substance are combined in a single mixture.
Claim 9
Dependent Claim
20 words
An osmotically driven device in accordance with claim 1 in which said wall consists essentially of said porous wall section.
Claim 10
Dependent Claim
24 words
An osmotically driven device in accordance with claim 1 further comprising a movable fluid-impermeable barrier dividing said beneficial agent and said osmotically active substance.
Claim 11
Dependent Claim
40 words
An osmotically driven device in accordance with claim 1 wherein said wall comprises a first and second wall sections, said first wall section being formed of said porous hydrophobic material and said first wall section surrounding said osmotically active substance.
Claim 12
Dependent Claim
22 words
An osmotically driven device in accordance with claim 10 in which said second wall section is formed of non-porous fluid impermeable material.
Claim 13
Dependent Claim
64 words
An osmotically driven device in accordance with claim 10 in which said first and second wall sections comprise a polymer selected from the group consisting of poly(lactic acid), poly(glycolic acid), and copolymers of lactic acid and glycolic acid, said first wall section defining pores of diameter ranging from 3 microns to 300 microns, and said second wall section being formed of nonporous, impermeable material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-17 | 2002-02-16 | 2002-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-17 | 2006-02-16 | 2006-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-17 | 2010-02-16 | 2010-08-18 | $7700.00 | Window Closed / Lapsed |