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US2668137A
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Vitamin b12 elution from charcoal
Assignee: Merck and Co Inc
•
Filing: 1949-12-13
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Granted: 1954-02-02
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Expires: 1969-12-13
Abstract
No abstract record available.
Inventors
- 👤 Stanford W Briggs
- 👤 Robert G Denkewalter
- 👤 George B Hughey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:52
CPC Classifications
A; A61; A61K; A61K31/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
THE PROCESS THAT COMPRISES ELUTING CHARCOAL, HAVING ABSORBED THEREON VITAMIN B12 ACTIVE SUBSTANCES ASSOCIATED WITH IMPURITIES, WITH A TWO-PHASE SYSTEM OF WATER AND AN ORGANIC POLAR SOLVENT INCOMPLETELY MISCIBLE WITH WATER, AND SEPARATING THE TWO PHASE OF THE RESULTING ELUTE TO RECOVER AN AQUEOUS SOLUTION CONTAINING AND VITAMIN B12 ACTIVE SUBSTANCES ESSENTIALLY FREE OF SAID IMPURITIES.
Claim 2
Dependent Claim
56 words
THE PROCESS THAT COMPRISES ELUTING CHARCOAL, HAVING ABSORBED THEREON VITAMIN B12 ACTIVE SUBSTANCES ASSOCIATED WITH IMPURITIES, WITH A TWO-PHASE SYSTEM OF WATER AND AN ORGANIC POLAR SOLVENT INCOMPLETELY MISCIBLE WITH WATER, AND SEPARATING THE TWO PHASE OF THE RESULTING ELUTE TO RECOVER AN AQUEOUS SOLUTION CONTAINING AND VITAMIN B12 ACTIVE SUBSTANCES ESSENTIALLY FREE OF SAID IMPURITIES.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-02-01 | 1957-08-03 | 1958-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-01 | 1961-08-03 | 1962-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-01 | 1965-08-03 | 1966-02-02 | $7700.00 | Window Closed / Lapsed |