US3641237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zero order release constant elution rate drug dosage
Assignee: National Patent Development Corp
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Filing: 1970-09-30
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Granted: 1972-02-08
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Expires: 1990-09-30
Abstract
Abstract ZERO ORDER RELEASE OF WATER SOLUBLE PHARMACEUTICALLY ACTIVE ORGANIC COMPOUNDS ALONE OR ABSORBED OR INCAPSULATED IN HYDROPHILIC POLYMERS IS OBTAINED BY PROVIDING A FILM DIFFUSION BARRIER OF AN ALKOXYETHYL ACRYLATE OR METHACRYLATE POLYMER. TO REDUCE IRRITATIN: AN OUTER COATING OF A NON-IRRITATING WATER SWELLABLE FILM CAN BE ALSO INCORPORATED.
Inventors
- 👤 Francis E Gould
- 👤 Thomas H Shephered
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:55
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0012; A61K9/0048; A61K9/0051; A61F; A61F9/00; A61F9/0008; A61F9/0017; A61K47/00; A61K47/30; A61K47/32
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |