Patent US2250156A successfully refreshed from Google Patents.
US4451452A
Expired / Lapsed
US
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Pharmaceutical compositions containing biodegradable polymers
Assignee: Fidelity Union Bank
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Filing: 1981-11-23
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Granted: 1984-05-29
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Expires: 2001-11-23
Abstract
Abstract Polymers formed by incomplete esterification of the hydroxy groups of a water-soluble polymer such as polyvinyl alcohol, amylose or dextran with a pharmacologically acceptable mono- or di-carboxylic acid to an extent sufficient to render the polymer water-insoluble although still water-swellable, are biodegradable. They are useful for the formulation of pharmaceutical compositions for parenteral administration, particularly in the form of injectable fine particles in which a drug is intimately mixed with or encapsulated by the polymer.
Inventors
- 👤 Heinrich Deibig
- 👤 Roland Reiner
- 👤 Hendricus B. A. Welle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:53
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5036; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1635; A61K9/1652; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027; A61K9/205; A61K9/2059; A61K9/5026; A61P; A61P11/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
105 words
A pharmaceutical composition comprising an effective amount of a parenterally effective drug in an injectable preparation in a sterile carrier liquid which preparation is an intimate mixture of a solid solution or dispersion of drug in a matrix of a biodegradable polymer or wholly or partly microencapsulated by a biodegradable polymer, said biodegradable polymer being a pharmacologically acceptable water-soluble polymer having hydroxy groups attached to the polymer chain, in which less than all of said hydroxy groups are esterified by residues of pharmacologically acceptable mono- or di-carboxylic acids, the degree of esterification being such that said biodegradable polymer is water-swellable but water-insoluble under physiological conditions.
Claim 2
Dependent Claim
105 words
A pharmaceutical composition comprising an effective amount of a parenterally effective drug in an injectable preparation in a sterile carrier liquid which preparation is an intimate mixture of a solid solution or dispersion of drug in a matrix of a biodegradable polymer or wholly or partly microencapsulated by a biodegradable polymer, said biodegradable polymer being a pharmacologically acceptable water-soluble polymer having hydroxy groups attached to the polymer chain, in which less than all of said hydroxy groups are esterified by residues of pharmacologically acceptable mono- or di-carboxylic acids, the degree of esterification being such that said biodegradable polymer is water-swellable but water-insoluble under physiological conditions.
Claim 3
Dependent Claim
53 words
A composition according to claim 1, in which the biodegradable polymer is based on a water-soluble polymer selected from poly(vinyl alcohol), dextran, a soluble starch product or a hydroxy-containing acrylic polymer, between 30% and 98% of the free hydroxyl groups of which are esterified with residues of pharmacologically acceptable mono- or di-carboxylic acids.
Claim 4
Dependent Claim
24 words
A composition according to claim 2, in which the water-soluble polymer is esterified with residues of a C 1 -C 10 straigh-chain fatty acid.
Claim 5
Dependent Claim
31 words
A composition according to claim 3 in which the fatty acid is formic acid or a C 2 -C 6 straight chain fatty acid having an even number of carbon atoms.
Claim 6
Dependent Claim
21 words
A composition according to claim 2 in which the biodegradable polymer is amylose acetate, PVA formate, amylose butyrate or dextran butyrate.
Claim 7
Dependent Claim
24 words
A composition according to claim 5 in which the biodegradable polymer is amylose butyrate or dextran butyrate and the pharmacologically active material is ketotifen.
Claim 8
Dependent Claim
16 words
A composition according to claim 1 comprising fine particles of mean diameter less than 100 μm.
Claim 9
Dependent Claim
20 words
A composition according to claim 7 in which the particles are suspended in an aqueous solution of a protective colloid.
References Cited (Backward Citations)
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Cited
GB810306A
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GB902369A
Cited
US3081233A
Cited
US3499962A
Cited
US3773919A
Cited
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US3978203A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |