US4657543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonically modulated polymeric devices for delivering compositions
Assignee: Massachusetts Institute of Technology
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Filing: 1984-07-23
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Granted: 1987-04-14
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Expires: 2004-07-23
Abstract
Abstract A composition such as a biologically active substance is delivered upon demand from a polymeric matrix by exposing the polymeric matrix containing the composition to ultrasonic energy.
Inventors
- 👤 Robert S. Langer
- 👤 Joseph Kost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:49
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0002; A61K9/0009; A61K41/00; A61K41/0047; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027; A61K9/2031; A61L; A61L27/00; A61L27/50; C; C08; C08G; C08G67/00; C08G67/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
125 words
A process for delivering a biologically active substance on demand comprising the steps of: combining a biologically active substance with a biocompatible polymeric composition as an admixture; forming said admixture into a shaped, solid polymeric matrix; implanting said solid polymeic matrix in-vivo at a preselected site such that said solid implanted matrix is in a liquid environment; and exposing said implanted solid polymeric matrix to ultrasonic energy for a predetermined time to effect cavitation of said solid polymeric matrix by rapid compression with subsequent expansion of liquid or solid surrounding said solid polymeric matrix thereby to control the rate of release of said biologically active substance from said matrix over a specific time period wherein the rate of release is changed during said time period.
Claim 2
Dependent Claim
125 words
A process for delivering a biologically active substance on demand comprising the steps of: combining a biologically active substance with a biocompatible polymeric composition as an admixture; forming said admixture into a shaped, solid polymeric matrix; implanting said solid polymeic matrix in-vivo at a preselected site such that said solid implanted matrix is in a liquid environment; and exposing said implanted solid polymeric matrix to ultrasonic energy for a predetermined time to effect cavitation of said solid polymeric matrix by rapid compression with subsequent expansion of liquid or solid surrounding said solid polymeric matrix thereby to control the rate of release of said biologically active substance from said matrix over a specific time period wherein the rate of release is changed during said time period.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said exposure to ultrasonic energy degrades said polymeric matrix.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein said polymeric matrix is a polyanhydride.
Claim 5
Dependent Claim
15 words
The process of claim 1 polymeric matrix is a copolymer of ethylene and vinyl acetate.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein said biologically active substance is a drug.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein said biologically active composition is insulin.
References Cited (Backward Citations)
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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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |