US4259331A
Expired / Lapsed
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Oxytetracycline compositions
Assignee: Pfizer Inc
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Filing: 1979-04-16
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Granted: 1981-03-31
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Expires: 1999-04-16
Abstract
Abstract Pharmaceutical compositions containing magnesium-calcium-oxytetracycline mixed chelates in aqueous 2-pyrrolidone solution are disclosed.
Inventors
- 👤 William W. Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:37
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/08; A61K9/0012; A61K9/0019; A61K31/00; A61K31/65; A61K33/00; A61K33/06; A61K33/08; A61P; A61P31/00; A61P31/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
An aqueous oxytetracycline composition comprising from about 20 to 30% w/v of oxytetracycline, from about 40 to 60% of 2-pyrrolidone, from about 0.8 to 0.95 molar proportions of magnesium oxide based on said oxytetracycline and from about 0.15 to 0.3 molar proportions based on said oxytetracycline of a pharmaceutically acceptable calcium compound soluble in said composition, said composition having a pH value in the range of from about 7.5 to 9.5.
Claim 2
Dependent Claim
71 words
An aqueous oxytetracycline composition comprising from about 20 to 30% w/v of oxytetracycline, from about 40 to 60% of 2-pyrrolidone, from about 0.8 to 0.95 molar proportions of magnesium oxide based on said oxytetracycline and from about 0.15 to 0.3 molar proportions based on said oxytetracycline of a pharmaceutically acceptable calcium compound soluble in said composition, said composition having a pH value in the range of from about 7.5 to 9.5.
Claim 3
Dependent Claim
22 words
A composition as claimed in claim 1 wherein said oxytetracycline is present at a level of from about 20 to 25% w/v.
Claim 4
Dependent Claim
19 words
A composition as claimed in claim 1 wherein said calcium compound is introduced in the form of calcium acetate.
Claim 5
Dependent Claim
33 words
A composition as claimed in claim 1 wherein polyvinylpyrrolidone having an average molecular weight of between about 5,000 and 100,000 is also present in a concentration of from about 1 to 15% w/v.
Claim 6
Dependent Claim
26 words
A composition as claimed in claim 1 wherein glycerol formal or propylene glycol is also present in a concentration of from about 1 to 15% w/v.
Claim 7
Dependent Claim
22 words
A composition as claimed in claim 1 wherein said 2-pyrrolidone is present in a concentration of from about 50 to 55% w/v.
Claim 8
Dependent Claim
87 words
An oxytetracycline composition comprising a solution in water of from about 20 to 25% w/v of oxytetracycline, from about 0.8 to 0.95 molar proportions based on said oxytetracycline of magnesium oxide, from about 0.15 to 0.3 molar proportions based on said oxytetracycline of calcium acetate, from about 50 to 55% w/v of 2-pyrrolidone and from about 1 to 15% w/v of polyvinylpyrrolidone having an average molecular weight of about 10,000 to 17,000, said composition having a pH value in the range of from about 8.5 to 9.
Claim 9
Dependent Claim
87 words
An oxytetracycline composition comprising a solution in water of from about 20 to 25% w/v of oxytetracycline, from about 0.8 to 0.95 molar proportions based on said oxytetracycline of magnesium oxide, from about 0.15 to 0.3 molar proportions based on said oxytetracycline of calcium acetate, from about 50 to 55% w/v of 2-pyrrolidone and from about 1 to 15% w/v of polyvinylpyrrolidone having an average molecular weight of about 10,000 to 17,000, said composition having a pH value in the range of from about 8.5 to 9.
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) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |