Patent US2683681A successfully refreshed from Google Patents.
US2683681A
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Method of purifying vitamin b12 material
Assignee: Wyeth Holdings LLC
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Filing: 1951-11-07
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Granted: 1954-07-13
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Expires: 1971-11-07
Abstract
No abstract record available.
Inventors
- 👤 Jerry Robert D Mccormick
- 👤 Siegfried A Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:40
CPC Classifications
A; A61; A61K; A61K31/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
28 words
THE METHOD OF PURIFYING VITAMIN B12 MATERIAL WHICH COMPRISES EXTRACTING A SOURCE OF SAID MATERIAL WITH A LIQUID NITROLIC ACID SOLVENT OF THE CLASS REPRESENTED BY THE FORMULA:
Claim 2
Independent Claim
28 words
THE METHOD OF PURIFYING VITAMIN B12 MATERIAL WHICH COMPRISES EXTRACTING A SOURCE OF SAID MATERIAL WITH A LIQUID NITROLIC ACID SOLVENT OF THE CLASS REPRESENTED BY THE FORMULA:
References Cited (Backward Citations)
US2563794A
Cited
US2530416A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-07-12 | 1958-01-11 | 1958-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-07-12 | 1962-01-11 | 1962-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-07-12 | 1966-01-11 | 1966-07-13 | $7700.00 | Window Closed / Lapsed |