US2960437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion exchange purification of basic antibiotics
Assignee: Pfizer Inc
•
Filing: 1955-02-23
•
Granted: 1960-11-15
•
Expires: 1975-02-23
Abstract
No abstract record available.
Inventors
- 👤 Ira J Friedman
- 👤 Edward G Martin
- 👤 Roy J Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:41
CPC Classifications
B; B01; B01J; B01J47/00; B01J47/014
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
134 words
A PROCESS FOR THE PURIFICATION OF A BASIC ANTIBIOTIC, WHICH COMPRISES CONTACTING AN IMPURE AQUEOUS SOLUTION OF SAID ANTIBIOTIC WITH A CARBOXYLIC ACID-TYPE ION-EXCHANGE RESIN OF LIMITED POROSITY WHICH IS A COPOLYMER OF METHACRYLIC ACID AND FROM ABOUT 6 TO ABOUT 12 PERCENT BY WEIGHT OF A DIVINYL HYDROCARBON AROMATIC COMPOUND AND WHICH IS AT AN EQUILIBRIUM PH OF ABOUT 7 TO 8, ELUTING THE ABSORBED ANTIBIOTIC FROM SAID RESIN WITH DILUTE AQUEOUS ACID, SOON THEREAFTER CONTACTING THE SOLUTION OF ELUTED ANTIBIOTIC THEREBY OBTAINED WITH A LOW POROSITY SULFONIC ACID-TYPE ION-EXCHANGE RESIN WHICH IS IN ITS ACID FORM AND IS A COPOLYMER OF A SULFONATED POLYSTYRENE AND FROM ABOUT 10 TO ABOUT 25 PERCENT BY WEIGHT OF A DIVINYL HYDROCARBON AROMATIC COMPOUND, AND ADJUSTING THE EFFLUENT TO A PH OF AT LEAST ABOUT 4.5.
Claim 2
Dependent Claim
134 words
A PROCESS FOR THE PURIFICATION OF A BASIC ANTIBIOTIC, WHICH COMPRISES CONTACTING AN IMPURE AQUEOUS SOLUTION OF SAID ANTIBIOTIC WITH A CARBOXYLIC ACID-TYPE ION-EXCHANGE RESIN OF LIMITED POROSITY WHICH IS A COPOLYMER OF METHACRYLIC ACID AND FROM ABOUT 6 TO ABOUT 12 PERCENT BY WEIGHT OF A DIVINYL HYDROCARBON AROMATIC COMPOUND AND WHICH IS AT AN EQUILIBRIUM PH OF ABOUT 7 TO 8, ELUTING THE ABSORBED ANTIBIOTIC FROM SAID RESIN WITH DILUTE AQUEOUS ACID, SOON THEREAFTER CONTACTING THE SOLUTION OF ELUTED ANTIBIOTIC THEREBY OBTAINED WITH A LOW POROSITY SULFONIC ACID-TYPE ION-EXCHANGE RESIN WHICH IS IN ITS ACID FORM AND IS A COPOLYMER OF A SULFONATED POLYSTYRENE AND FROM ABOUT 10 TO ABOUT 25 PERCENT BY WEIGHT OF A DIVINYL HYDROCARBON AROMATIC COMPOUND, AND ADJUSTING THE EFFLUENT TO A PH OF AT LEAST ABOUT 4.5.
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) | 1963-11-15 | 1964-05-16 | 1964-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-15 | 1968-05-16 | 1968-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-15 | 1972-05-16 | 1972-11-15 | $7700.00 | Window Closed / Lapsed |