US4772473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitrofurantoin dosage form
Assignee: Warner Chilcott Pharmaceuticals Inc
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Filing: 1986-06-16
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Granted: 1988-09-20
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Expires: 2006-06-16
Abstract
Abstract The invention involves a combination sustained release/rapid release pharmaceutical capsule for oral administration of nitrofurantoin comprising, in a capsule shell, a first layer of a first particulate mixture comprising nitrofurantoin, polyvinylpyrrolidone and carboxyvinylpolymer; and a second layer of a second particulate mixture comprising macrocrystalline nitrofurantoin.
Inventors
- 👤 Vikram S. Patel
- 👤 Harry L. Welles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:27
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/33; A61K31/395; A61K31/41; A61K31/4164; A61K31/4178; A61K9/00; A61K9/48; A61K9/50; A61K9/5084; A61P; A61P31/00; A61P31/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
120 words
A controlled release pharmaceutical composition for oral administration of nitrofurantoin to a human subject, comprising: (1) a first layer of a first flowable, particulate mixture consisting essentially of (a) from about 10% to about 90% of nitrofurantoin (b) from about 5% to about 86% of polyvinylpyrrolidone; and (c) from about 4% to about 40% of carboxyvinylpolymer; wherein said polyvinylpyrrolidone and said carboxyvinylpolymer occur substantially entirely in separate particles of said first particulate mixture; and (2) a second layer of a second flowable, particulate mixture comprising macrocrystalline nitrofurantoin; in a capsule shell which is soluble in gastrointestinal juice, wherein said composition, when administered to said subject, provides rapid release and sustained release of nitrofurantoin with low incidence of nausea and emesis.
Claim 2
Dependent Claim
120 words
A controlled release pharmaceutical composition for oral administration of nitrofurantoin to a human subject, comprising: (1) a first layer of a first flowable, particulate mixture consisting essentially of (a) from about 10% to about 90% of nitrofurantoin (b) from about 5% to about 86% of polyvinylpyrrolidone; and (c) from about 4% to about 40% of carboxyvinylpolymer; wherein said polyvinylpyrrolidone and said carboxyvinylpolymer occur substantially entirely in separate particles of said first particulate mixture; and (2) a second layer of a second flowable, particulate mixture comprising macrocrystalline nitrofurantoin; in a capsule shell which is soluble in gastrointestinal juice, wherein said composition, when administered to said subject, provides rapid release and sustained release of nitrofurantoin with low incidence of nausea and emesis.
Claim 3
Dependent Claim
28 words
The capsule of claim 1 wherein said first particulate mixture comprises from about 10% to about 70% of polyvinylpyrrolidone, and said capsule shell is soluble in gastric juice.
Claim 4
Dependent Claim
35 words
The capsule of claim 1 wherein said first particulate mixture comprises from about 15% to about 60% of polyvinylpyrrolidone, and said capsule shell is a hard gelatin capsule shell which is soluble in gastric juice.
Claim 5
Dependent Claim
19 words
The capsule of claim 2 wherein said first particulate mixture comprises from about 5% to about 25% of carboxyvinylpolymer.
Claim 6
Dependent Claim
33 words
The capsule of claim 3 wherein said first particulate mixture comprises from about 20% to about 70% of nitrofurantoin acid, or a hydrate thereof, and from about 5% to about 15% of carboxyvinylpolymer.
Claim 7
Dependent Claim
33 words
The capsule of claim 2 wherein said first particulate mixture comprises from about 30% to about 70% of nitrofurantoin acid, or a hydrate thereof, and from about 7% to about 10% of carboxyvinylpolymer.
Claim 8
Dependent Claim
27 words
The capsule of claim 4 wherein said carboxyvinylpolymer has a molecular weight of at least about 1,250,000, and said capsule shell is a hard gelatin capsule shell.
Claim 9
Dependent Claim
40 words
The capsule of claim 5 wherein said carboxyvinylpolymer has a molecular weight of about 3,000,000 and is a polyacrylic acid cross-linked with about 1% of polyallyl sucrose having an average of about 5.8 allyl groups for each molecule of sucrose.
Claim 10
Dependent Claim
40 words
The capsule of claim 6 wherein said carboxyvinylpolymer has a molecular weight of about 3,000,000 and is a polyacryllic acid cross-linked with about 1% of polyallyl sucrose having an average of about 5.8 allyl groups for each molecule of sucrose.
Claim 11
Dependent Claim
19 words
The capsule of claim 8 where said polyvinylpyrrolidone has a molecular weight of from about 7,000 to about 700,000.
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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) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |