Patent US4555399A successfully refreshed from Google Patents.
US4555399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aspirin tablet
Assignee: Key Pharmaceuticals Inc
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Filing: 1984-03-08
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Granted: 1985-11-26
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Expires: 2004-03-08
Abstract
Abstract A tablet, which readily disintegrates in gastric fluid to give aspirin crystals coated with a polymeric film preventing the aspirin crystals from contacting the stomach wall but not preventing access of gastric fluid to the aspirin contained within the polymer film, which consists of a plurality of aspirin crystals 20-60 mesh in size coated with about 3-10% by weight of a polymeric mixture comprising from about 1.5 to about 15 parts by weight ethylcellulose and about one part by weight hydroxypropylcellulose; a compression aid; a disintegrant; and a tableting aid.
Inventors
- 👤 Charles H. Hsiao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:24
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2072; A61K9/2077; A61K9/2081; A61K31/00; A61K31/60; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5036; A61K9/5042; A61K9/5047
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
A tablet that readily disintegrates in gastric fluid to give aspirin crystals coated with a polymeric film preventing the aspirin crystals from contacting the stomach wall but not preventing access of gastric fluid to the aspirin contained within the polymer film, which consists of a plurality of aspirin crystals 20-60 mesh in size coated with about 3-10% by weight of a polymeric mixture of about 1.5 to about 15 parts by weight ethylcellulose and about one part by weight hydroxypropylcellulose; a compression aid; a disintegrant; and a tableting aid.
Claim 2
Dependent Claim
89 words
A tablet that readily disintegrates in gastric fluid to give aspirin crystals coated with a polymeric film preventing the aspirin crystals from contacting the stomach wall but not preventing access of gastric fluid to the aspirin contained within the polymer film, which consists of a plurality of aspirin crystals 20-60 mesh in size coated with about 3-10% by weight of a polymeric mixture of about 1.5 to about 15 parts by weight ethylcellulose and about one part by weight hydroxypropylcellulose; a compression aid; a disintegrant; and a tableting aid.
Claim 3
Dependent Claim
15 words
A tablet according to claim 1 wherein the crystals are about 40 mesh in size.
Claim 4
Dependent Claim
15 words
A tablet according to claim 1 wherein the ratio of ethylcellulose to hydroxypropylcellulose is 4:1.
Claim 5
Dependent Claim
12 words
A tablet according to claim 1 containing about 1000 mg of aspirin.
Claim 6
Dependent Claim
13 words
A tablet according to claim 1 wherein said compression aid is microcrystalline cellulose.
Claim 7
Dependent Claim
12 words
A tablet according to claim 1 wherein said disintegrant is cross-linked polyvinylpyrrolidone.
Claim 8
Dependent Claim
14 words
A tablet according to claim 1 wherein said tableting aid is hydrogenated vegetable oil.
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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) | 1988-11-25 | 1989-05-27 | 1989-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-25 | 1993-05-27 | 1993-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-25 | 1997-05-27 | 1997-11-26 | $7700.00 | Window Closed / Lapsed |