US2528022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of antibiotics by ion exchange procedures
Assignee: Pfizer Inc
•
Filing: 1945-01-27
•
Granted: 1950-10-31
•
Expires: 1965-01-27
Abstract
No abstract record available.
Inventors
- 👤 Robert Wayne Van Dolah
- 👤 George L Christenson
- 👤 Robert S Shelton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:28
CPC Classifications
B; B01; B01J; B01J47/00; B01J47/014
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
70 words
A PROCESS FOR RECOVERING AN ANTIBIOTIC OF THE CLASS CONSISTING OF STREPTOMYCIN, STREPTOTHRICIN AND TYROCIDIN, FROM A DILUTE AQUEOUS SOLUTION IN WHICH IT IS MIXED WITH INORGANIC SALT IMPURITIES, WHICH COMPRISES PASSING SAID SOLUTION OVER AN ORGANIC CATION EXCHANGE MATERIAL CONTAINING ACIDIC GROUPS UNTIL A SUBSTANTIAL AMOUNT OF ANTIBIOTIC IS ADSORBED THEREON, ELUTING THE ANTIBIOTIC THEREFROM WITH A DILUTE SOLUTION OF AN ACID, AND RECOVERING THE ANTIBIOTIC FROM THE ELUATE.
References Cited (Backward Citations)
US2443485A
Cited
US2104501A
Cited
FR805092A
Cited
US2226389A
Cited
US2293954A
Cited
US2285750A
Cited
US2408615A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-10-30 | 1954-05-01 | 1954-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-10-30 | 1958-05-01 | 1958-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-10-30 | 1962-05-01 | 1962-10-31 | $7700.00 | Window Closed / Lapsed |