US4016880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Osmotically driven active agent dispenser
Assignee: Alza Corp
•
Filing: 1976-03-04
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Granted: 1977-04-12
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Expires: 1996-03-04
Abstract
Abstract Osmotically driven active agent dispenser for use in an aqueous environment that pumps a solution of active agent, such as a drug, at a predetermined, constant rate. The dispenser is in the form of a coated tablet comprising: a core of an osmotically effective active agent composition; and an inexpandable wall that encloses the core, has a controlled permeability to water and includes means, such as brittleness or sites of structural weakness, that is responsive to the pressure generated within the dispenser by imbibition of water from the environment by the core through the wall to form at least one, and usually many, passageways in situ in the wall through which the active agent composition in solution is pumped osmotically at a rate that is substantially dependent of the rate at which water is being imbibed into the dispenser.
Inventors
- 👤 Felix Theeuwes
- 👤 Nalinkant C. Damani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:15
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0002; A61K9/0004; A61F; A61F9/00; A61F9/0008; A61F9/0017
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
An osmotically driven active agent dispenser for use in an aqueous environment comprising: a. a core of an osmotically effective pressure generating active agent composition; and b. a substantially inexpandable wall having a substantially intact surface enclosing the core, said wall being substantially impermeable to the active agent composition and having a controlled permeability to water and including, c. means responsive to the pressure generated within the dispenser by imbibition of water from the environment by the core through the wall to create and form at least one exit passageway in situ in the wall through which the active agent composition in solution is pumped osmotically from the core into the environment at a substantially predetermined, substantially constant rate.
Claim 2
Dependent Claim
119 words
An osmotically driven active agent dispenser for use in an aqueous environment comprising: a. a core of an osmotically effective pressure generating active agent composition; and b. a substantially inexpandable wall having a substantially intact surface enclosing the core, said wall being substantially impermeable to the active agent composition and having a controlled permeability to water and including, c. means responsive to the pressure generated within the dispenser by imbibition of water from the environment by the core through the wall to create and form at least one exit passageway in situ in the wall through which the active agent composition in solution is pumped osmotically from the core into the environment at a substantially predetermined, substantially constant rate.
Claim 3
Dependent Claim
28 words
The dispenser of claim 1 wherein the active agent composition in solution exhibits an osmotic pressure that is significantly greater than the osmotic pressure of the aqueous environment.
Claim 4
Dependent Claim
12 words
The dispenser of claim 1 wherein the active agent is a drug.
Claim 5
Dependent Claim
21 words
The dispenser of claim 3 wherein the composition in solution exhibits an osmotic pressure of about 20,000 to about 40,000 kPa.
Claim 6
Dependent Claim
16 words
The dispenser of claim 1 wherein the wall is about 100 to about 500 microns thick.
Claim 7
Dependent Claim
18 words
The dispenser of claim 1 wherein the means is an inherent property of the material forming the wall.
Claim 8
Dependent Claim
16 words
The dispenser of claim 1 wherein the means is sites of structural weakness in the wall.
Claim 9
Dependent Claim
43 words
The dispenser of claim 7 wherein the sites are the result of incorporating a foreign material into the material forming the wall, forming the wall from mutually incompatible polymers, treating the wall thermally, solvent crazing the wall, or subjecting the wall to irradiation.
Claim 10
Dependent Claim
21 words
The dispenser of claim 1 wherein there is more than one passageway and the passageways are irregularly shaped, sized, and positioned.
Claim 11
Dependent Claim
29 words
The dispenser of claim 1 wherein the passageway is in the form of a network of cracks extending over at least a part of the surface of the dispenser.
Claim 12
Dependent Claim
18 words
The dispenser of claim 1 wherein the passageway is in the form of a plurality of discrete holes.
References Cited (Backward Citations)
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US3146169A
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US3247066A
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US3538214A
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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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |