US4765990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sustained-release nifedipine preparation
Assignee: Kanebo Ltd
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Filing: 1987-04-21
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Granted: 1988-08-23
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Expires: 2007-04-21
Abstract
Abstract A novel sustained-release nifedipine preparation which comprises the following Composition (A) and Composition (B) in a ratio of 15:85 to 50:50 by weight of nifedipine, Composition (A): a rapid-release preparation containing as an active ingredient nifedipine fine powder having an average particle size of not more than 5μ, Composition (B): a delayed-release preparation containing as the active ingredient nifedipine fine powder having an average particle size of not more than 5μ and having a surface coating layer comprising a non-toxic, hardly water-soluble substance and an enteric high molecular compound.
Inventors
- 👤 Isao Sugimoto
- 👤 Kazunori Togo
- 👤 Kozo Sasaki
- 👤 Atsushi Yamagata
- 👤 Akira Kuchiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:02
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/33; A61K31/395; A61K31/435; A61K31/44; A61K9/00; A61K9/48; A61K9/50; A61K9/5084
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A non-compressed sustained-release nifedipine preparation consisting essentially of the following Composition (A) and Composition (B) in a ratio of 15:85 to 50:50 by weight of nifedipine, Composition (A): a rapid-release preparation containing as an active ingredient nifedipine crystalline fine powder having an average particle size of not more than 5 microns in admixture with a pharmaceutically acceptable carrier, Composition (B): a delayed-release preparation containing as the active ingredient nifedipine fine powder having an average particle size of not more than 5 microns and having a surface coating layer comprising a non-toxic, hardly water-soluble substance selected from the group consisting of ethyl cellulose, hydrogenated soybean oil and glycerin monostearate, and an enteric high molecular compound selected from the group consisting of cellulose acetate phthalate, hydroxypropylmethyl cellulose phthalate and methacrylic acid methyl methacrylate copolymer in a weight ratio of 1:5 to 5:1.
Claim 2
Dependent Claim
140 words
A non-compressed sustained-release nifedipine preparation consisting essentially of the following Composition (A) and Composition (B) in a ratio of 15:85 to 50:50 by weight of nifedipine, Composition (A): a rapid-release preparation containing as an active ingredient nifedipine crystalline fine powder having an average particle size of not more than 5 microns in admixture with a pharmaceutically acceptable carrier, Composition (B): a delayed-release preparation containing as the active ingredient nifedipine fine powder having an average particle size of not more than 5 microns and having a surface coating layer comprising a non-toxic, hardly water-soluble substance selected from the group consisting of ethyl cellulose, hydrogenated soybean oil and glycerin monostearate, and an enteric high molecular compound selected from the group consisting of cellulose acetate phthalate, hydroxypropylmethyl cellulose phthalate and methacrylic acid methyl methacrylate copolymer in a weight ratio of 1:5 to 5:1.
Claim 3
Dependent Claim
23 words
The sustained-release nifedipine preparation according to claim 1, wherein the nifedipine fine powder has an average particle size of 1 to 4 microns.
Claim 4
Dependent Claim
22 words
The sustained-release nifedipine preparation according to claim 2, wherein the nifedipine fine powder has an average particle size of about 2 microns.
Claim 5
Dependent Claim
30 words
The sustained-release nifedipine preparation according to claim 1, wherein the hardly water-soluble substance and the enteric high molecular compound are mixed in a ratio of 1:2 to 2:1 by weight.
Claim 6
Dependent Claim
27 words
The sustained-release nifedipine preparation according to claim 1, wherein Composition (A) and Composition (B) are mixed in a ratio of 20:80 to 40:60 by weight of nifedipine.
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) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |