US3597450A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of glycolide polymerizable into polyglycolic acid of consistently high molecular weight
Assignee: Wyeth Holdings LLC
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Filing: 1969-11-05
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Granted: 1971-08-03
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Expires: 1989-11-05
Abstract
Abstract WHEREAS RECRYSTALLIZATION ALONE, OR SUBLIMATION ALONE, OF IMPURE GLYCOLIDE DOES NOT, IN THE MAJORITY OF CASES, RENDER GLYCOLIDE SUFFICIENTLY PURE TO PERMIT ITS POLYMERIZATION INTO POLYGLYCOLIC ACID OF THE HIGH MOLECULAR WEIGHT VARIETY REQUIRED FOR USE AS AN ABSORBABLE SURGICAL SUTURE OR LIGATURE, IT IS SURPRISINGLY FOUND THAT WHEN IMPURE GLYCOLIDE IS SUBJECTED TO THE DUAL SEQUENTIAL STEPS OF RECRYSTALLIZATION AND SUBLIMATION, THE GLYCOLIDE PRODUCED IS SUFFICIENTLY PURE TO PRODUCE CONSISTENTLY HIGH MOLECULAR WEIGHT POLYGLYCOLIC ACID, PROVIDED THE SUBLIMATION STEP FOLLOWS THE RECRYSTALLIZATION STEP.
Inventors
- 👤 Edward Emil Schmitt
- 👤 Rocco Albert Polistina
- 👤 Martin Epstein
- 👤 David Anthony Deprospero
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:57
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; C07; C07D; C07D319/00; C07D319/10; C07D319/12
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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |