Patent US2650216A successfully refreshed from Google Patents.
US2650216A
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Crystalline naphthalene sulfonate salts of streptomycin and dihydrostreptomycin
Assignee: Pfizer Inc
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Filing: 1949-03-29
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Granted: 1953-08-25
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Expires: 1969-03-29
Abstract
No abstract record available.
Inventors
- 👤 Rudolph A Carboni
- 👤 Peter P Regna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:56
CPC Classifications
C; C07; C07H; C07H15/00; C07H15/20; C07H15/22; C07H15/238
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
52 words
A PROCESS WHICH COMPRISES NEUTRALIZING WITH NAPHTHALENE B-SULFONIC ACID AND ALKALINE WATER SOLUTION OF A WATER-SOLUBLE SALT OF AN ANTIBIOTIC SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF STREPTOMYCIN AND DIHYDROSTREPTOMYCIN, COOLING THE RESULTING SOLUTION UNTIL CRYSTALLIZATION OF THE NAPHTHALENE B-SULFONIC ACID SALT OF THE ANTIBIOTIC SUBSTANCE OCCURS AND RECOVERING THE CRYSTALLINE SALT.
Claim 2
Dependent Claim
18 words
SALTS OF NAPHTHALENE B-SULFONIC ACID AND AN ANTIBIOTIC SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF STREPTOMYCIN AND DIHYDROSTREPTOMYCIN.
References Cited (Backward Citations)
US2462175A
Cited
US2501014A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-08-24 | 1957-02-23 | 1957-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-08-24 | 1961-02-23 | 1961-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-08-24 | 1965-02-23 | 1965-08-25 | $7700.00 | Window Closed / Lapsed |