US2658077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystallization of chlortetracycline
Assignee: Wyeth Holdings LLC
•
Filing: 1949-08-20
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Granted: 1953-11-03
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Expires: 1969-08-20
Abstract
No abstract record available.
Inventors
- 👤 Edward R Harms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:25
CPC Classifications
C; C07; C07C; C07C233/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
90 words
A METHOD OF ISOLATING CHLORTETRACYCLINE AS AN ACID SALT WHICH COMPRISES ADDING IN INORGANIC WATER-SOLUBLE SALT OF A MINERAL ACID AND AN AT LEAST PARTIALLY WATER-SOLUBLE HYDROXYLATED ORGANIC SOLVENT IN A QUANTITY INSUFFICIENT TO DISSOLVE THE CHLORTETRACYCLINE PRESENT TO AN AQUEOUS SOLUTION CONTAINING CHLORTETRACYCLINE AT A PH OF LESS THAN 4 AND A CONCENTRATION OF APPROXIMATELY 3 TO 30 MILLIGRAMS PER MILLIMETER, AND SEPARATING AND RECOVERING THE THUS FORMED SALT OF CHLORTETRACYCLINE, WITH AN ACID, SAID ACID BEING THE ACID DERIVED FROM THE ANIONIC PORTION OF SAID INORGANIC WATER-SOLUBLE SALT.
References Cited (Backward Citations)
US2482055A
Cited
US2481763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-02 | 1957-05-04 | 1957-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-02 | 1961-05-04 | 1961-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-02 | 1965-05-04 | 1965-11-03 | $7700.00 | Window Closed / Lapsed |