US4793997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled delivery device
Assignee: Nortel Networks Ltd
•
Filing: 1987-06-29
•
Granted: 1988-12-27
•
Expires: 2007-06-29
Abstract
Abstract A device for the controlled release of an active material into an aqueous medium, e.g. body fluids, comprises a water soluble glass container in which the active material is sealed. The container wall has a region of reduced thickness which region dissolves before the remainder of the container wall to release the active material.
Inventors
- 👤 Cyril F. Drake
- 👤 Alfred J. Arch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:35
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0087; A61K9/0092; A61K9/20; A61K9/28; A61K9/2806; A61K9/2813; A61M; A61M31/00; A61M31/002; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/131; Y10T428/1317; Y10T428/249921; Y10T428/249994; Y10T428/249995; Y10T428/249997
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
109 words
A device for the timed release of an active material into an aqueous medium, the device comprising a sealed container having a wall consisting of a water soluble glass and in which container the active material is encapsulated, wherein a minor proportion of container wall consists of a region of reduced resistance to solution attack whereby, when the device is contacted by the aqueous medium, that region is dissolved over a predetermined time period to provide an opening in the container wall so as to release the active material whilst the remainder of the glass container wall is only partially dissolved so as to prevent collapse of the container.
Claim 2
Independent Claim
109 words
A device for the timed release of an active material into an aqueous medium, the device comprising a sealed container having a wall consisting of a water soluble glass and in which container the active material is encapsulated, wherein a minor proportion of container wall consists of a region of reduced resistance to solution attack whereby, when the device is contacted by the aqueous medium, that region is dissolved over a predetermined time period to provide an opening in the container wall so as to release the active material whilst the remainder of the glass container wall is only partially dissolved so as to prevent collapse of the container.
Claim 3
Dependent Claim
19 words
A device as claimed in claim 1, wherein the reduced resistance region comprises a region of reduced wall thickness.
Claim 4
Dependent Claim
20 words
A device as claimed in claim 2, wherein said reduced thickness region comprises a groove provided in the device wall.
Claim 5
Dependent Claim
15 words
A device as claimed in claim 1, wherein the glass is a phosphorus pentoxide glass.
Claim 6
Dependent Claim
15 words
A device as calimed in claim 1, wherein the glass is a phosphorus pentoxide glass.
Claim 7
Dependent Claim
26 words
A device as claimed in claim 4, wherein said glass includes a modifying oxide selected from the group comprising calcium oxide, zinc oxide and mixtures thereof.
Claim 8
Independent Claim
122 words
A device for the timed release of an active material into an aqueous medium, the device comprising a sealed tubular container having a wall consisting of a water soluble glass and in which container the active material is encapsulated, wherein the container wall has cylindrical inner and outer major surfaces, the two cylindrical surfaces being non co-axial so as to provide a region of reduced thickness in the container wall whereby, when the device is contacted by the aqueous medium, the region of reduced wall thickness is dissolved to provide an opening in the container wall so as to release the active material whilst the remainder of the container wall is only partially dissolved so as to prevent collapse of the container.
Claim 9
Independent Claim
122 words
A device for the timed release of an active material into an aqueous medium, the device comprising a sealed tubular container having a wall consisting of a water soluble glass and in which container the active material is encapsulated, wherein the container wall has cylindrical inner and outer major surfaces, the two cylindrical surfaces being non co-axial so as to provide a region of reduced thickness in the container wall whereby, when the device is contacted by the aqueous medium, the region of reduced wall thickness is dissolved to provide an opening in the container wall so as to release the active material whilst the remainder of the container wall is only partially dissolved so as to prevent collapse of the container.
References Cited (Backward Citations)
US4218255A
Cited
US4283227A
Cited
US4349025A
Cited
US4407786A
Cited
US4350675A
Cited
US4449981A
Cited
US4473545A
Cited
US4517006A
Cited
US4482541A
Cited
US4587267A
Cited
US4519866A
Cited
US4678659A
Cited
US4645749A
Cited
US4662879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |