US5019723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-regulated therapeutic agent delivery system and method
Assignee: Controlled Release Technologies Inc
•
Filing: 1989-10-02
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Granted: 1991-05-28
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Expires: 2009-10-02
Abstract
Abstract A self-regulated system and method for controllably administering a therapeutic agent to a patient is disclosed. A therapeutic agent is driven by unidirectional electrostatic diffusion across a rate-controlling electret membrane. The diffused therapeutic agent is then delivered to a patient. The preparation of the electret membrane and therapeutic agent delivery apparatus are also disclosed.
Inventors
- 👤 Loi H. Tran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:28
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/14; A61M5/1407; Y; Y10; Y10S; Y10S55/00; Y10S55/39
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
73 words
A method of preparing an electret membrane comprising a polyelectrolyte salt and a porous hydrophilic polymer matrix having a charge modified ionic surface comprising the steps of: providing the polymer matrix; providing a solution of polyelectrolyte salt; impregnating the polymer matrix by immersion in the polyelectrolyte solution; elevating the temperature of the polyelectrolyte solution; maintaining the immersed polymer matrix at the elevated temperature to form an electret membrane; and drying the electret membrane.
Claim 2
Independent Claim
73 words
A method of preparing an electret membrane comprising a polyelectrolyte salt and a porous hydrophilic polymer matrix having a charge modified ionic surface comprising the steps of: providing the polymer matrix; providing a solution of polyelectrolyte salt; impregnating the polymer matrix by immersion in the polyelectrolyte solution; elevating the temperature of the polyelectrolyte solution; maintaining the immersed polymer matrix at the elevated temperature to form an electret membrane; and drying the electret membrane.
Claim 3
Dependent Claim
9 words
The membrane formed by the method of claim 1.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the polyelectrolyte is sodium polystyrene sulfonate.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein the polymer matrix comprises a modified Nylon film having amine groups and carboxyl groups on its surface.
Claim 6
Dependent Claim
35 words
An electret membrane comprised of a charge modified Nylon film having 50 percent amine groups and 50 percent carboxyl groups on its surface and impregnated with sodium polystyrene sulfonate by the method of claim 3.
References Cited (Backward Citations)
US3967027A
Cited
US3660736A
Cited
US3793715A
Cited
JPS50650A
Cited
US4035164A
Cited
JPS5245097A
Cited
GB2060259A
Cited
US4720345A
Cited
US4889636A
Cited
US4513049A
Cited
US4473863A
Cited
US4789504A
Cited
US4626263A
Cited
US4874659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-27 | 1994-11-26 | 1995-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-27 | 1998-11-26 | 1999-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-27 | 2002-11-26 | 2003-05-28 | $7700.00 | Window Closed / Lapsed |