Patent US5516522A successfully refreshed from Google Patents.
US5516522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biodegradable porous device for long-term drug delivery with constant rate release and method of making the same
Assignee: Louisiana State University
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Filing: 1994-03-14
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Granted: 1996-05-14
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Expires: 2014-03-14
Abstract
Abstract A biodegradable porous drug delivery device for controllably releasing a pharmacological agent is disclosed which comprises a hollow tube closed at both ends having an interior surface and an exterior surface, the tube formed of a mixture of polycaprolactone and a pore-creating agent, the tube further comprising channels formed between the interior surface and the exterior surface and a pharmacological agent filled into the hollow tube for controllable release through the channels of the tube. Methods of manufacturing the biodegradable porous drug delivery device are also disclosed.
Inventors
- 👤 Gholam A. Peyman
- 👤 Dachuan Yang
- 👤 Bahram Khoobehi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:44
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0087; A61K9/0092; A61F; A61F9/00; A61F9/0008; A61F9/0017; A61K9/0012; A61K9/0048; A61K9/0051; A61M; A61M31/00; A61M31/002
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
115 words
A biodegradable porous drug delivery device for controllably releasing an effective amount of a pharmacological agent, the device comprising: a hollow tube having an interior surface and an exterior surface and a first end and a second end, the tube formed of a mixture of polycaprolactone and a pore-creating agent and further having channels formed between the interior surface and the exterior surface; and a pharmacological agent filled into the hollow tube for controllable release through the channels of the tube, the first end being heat sealed prior to the pharmacological agent being filled into the hollow tube and the second end being heat sealed after the pharmacological agent is filled into the hollow tube.
Claim 2
Dependent Claim
115 words
A biodegradable porous drug delivery device for controllably releasing an effective amount of a pharmacological agent, the device comprising: a hollow tube having an interior surface and an exterior surface and a first end and a second end, the tube formed of a mixture of polycaprolactone and a pore-creating agent and further having channels formed between the interior surface and the exterior surface; and a pharmacological agent filled into the hollow tube for controllable release through the channels of the tube, the first end being heat sealed prior to the pharmacological agent being filled into the hollow tube and the second end being heat sealed after the pharmacological agent is filled into the hollow tube.
Claim 3
Dependent Claim
33 words
The device of claim 1 further comprising a second pharmacological agent filled into the hollow tube for controllable release through the channels of the tube when the device is inserted into a body.
Claim 4
Dependent Claim
15 words
The device of claim 1 wherein the pore-creating agent is an inert water soluble material.
Claim 5
Dependent Claim
29 words
The device of claim 3 wherein the channels are formed when the pore-creating agent comes into contact with an aqueous solution to dissolve the pore-creating agent within the device.
Claim 6
Dependent Claim
29 words
The device of claim 3 wherein the inert water soluble material comprises particles and the particles are of the same size to form the channels of the same size.
Claim 7
Dependent Claim
26 words
The device of claim 3 wherein the inert water soluble material comprises particles and the particles are of different sizes to form channels of different sizes.
Claim 8
Dependent Claim
24 words
The device of claim 1 wherein the density of the channels is greater with the greater amount of pore-creating agent incorporated with the polycaprolactone.
Claim 9
Dependent Claim
17 words
The device of claim 1 wherein the polycaprolactone has a viscosity-average molecular weight between 11,000 to 100,000.
Claim 10
Dependent Claim
24 words
The device of claim 1 wherein the density of the channels is small with the smaller amount of pore-creating agent incorporated with the polycaprolactone.
Claim 11
Dependent Claim
25 words
The device of claim 1 wherein the tube is formed by heating the mixture at a temperature between about 60° C. and about 180° C.
Claim 12
Dependent Claim
23 words
The device of claim 10 wherein the preferred temperature range of heating the mixture is between about 100° C. and about 140° C.
Claim 13
Dependent Claim
21 words
The device of claim 1 wherein the polycaprolactone has a preferred viscosity-average molecular weight in the range between 30,000 and 60,000.
Claim 14
Dependent Claim
20 words
The device of claim 1 wherein the weight % of pore-creating agent to polycaprolactone is in the range of 0%-70%.
Claim 15
Dependent Claim
20 words
The device of claim 13 wherein the weight % of pore-creating agent to polycaprolactone has a preferred range of 5%-30%.
Claim 16
Dependent Claim
18 words
The device of claim 1 wherein the pore-creating agent has a mesh size between about 100 and 400.
Claim 17
Dependent Claim
19 words
The device of claim 15 wherein the preferred range for the mesh size is between about 140 and 350.
References Cited (Backward Citations)
US4666704A
Cited
US5324519A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-14 | 1999-11-13 | 2000-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-14 | 2003-11-13 | 2004-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-14 | 2007-11-13 | 2008-05-14 | $7700.00 | Window Closed / Lapsed |