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Patent US2531869A successfully refreshed from Google Patents.
US2531869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of recovering and purifying streptomycin
Assignee: Wyeth LLC
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Filing: 1946-01-26
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Granted: 1950-11-28
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Expires: 1966-01-26
Abstract
No abstract record available.
Inventors
- 👤 Harvey E Alburn
- 👤 Eric G Snyder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:30
CPC Classifications
C; C07; C07H; C07H15/00; C07H15/20; C07H15/22; C07H15/238
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
THE METHOD OF ENHANCING THE POTENCY OF A CRUDE STREPTOMYCIN SALT CONTAINED IN DILUTE SOLUTION IN A SUBSTANTIALLY WATER-FREE LOWER ALCOHOL WHICH COMPRISES ADDING PHOSPHATE ION TO THE SOLUTION WITHOUT SUBSTANTIAL ADDITION OF WATER THERETO, AND SELECTIVELY PRECIPITATING A STREPTOMYCIN PHOSPHATE OF ENHANCED POTENCY FROM THE SOLUTION AT A PH NOT ABOVE ABOUT 4 BY ADDING TO THE SOLUTION A LIQUID NON-SOLVENT FOR THE STREPTOMYCIN PHOSPHATE WHICH IS MISCIBLE WITH THE LOWER ALCOHOL.
Claim 2
Independent Claim
73 words
THE METHOD OF ENHANCING THE POTENCY OF A CRUDE STREPTOMYCIN SALT CONTAINED IN DILUTE SOLUTION IN A SUBSTANTIALLY WATER-FREE LOWER ALCOHOL WHICH COMPRISES ADDING PHOSPHATE ION TO THE SOLUTION WITHOUT SUBSTANTIAL ADDITION OF WATER THERETO, AND SELECTIVELY PRECIPITATING A STREPTOMYCIN PHOSPHATE OF ENHANCED POTENCY FROM THE SOLUTION AT A PH NOT ABOVE ABOUT 4 BY ADDING TO THE SOLUTION A LIQUID NON-SOLVENT FOR THE STREPTOMYCIN PHOSPHATE WHICH IS MISCIBLE WITH THE LOWER ALCOHOL.
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) | 1953-11-27 | 1954-05-29 | 1954-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-27 | 1958-05-29 | 1958-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-27 | 1962-05-29 | 1962-11-28 | $7700.00 | Window Closed / Lapsed |