US4894239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sustained-release preparation and production thereof
Assignee: Takeda Pharmaceutical Co Ltd
•
Filing: 1988-05-16
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Granted: 1990-01-16
•
Expires: 2008-05-16
Abstract
Abstract The present invention concerns a sustained-release microcapsule preparation comprising an ion exchange resin with 6 to 16% crosslinking, containing a drug adsorbed in an amount not less than 80% of its theoretical ion adsorption amount and coated with a water-permeable polymer.
Inventors
- 👤 Muneo Nonomura
- 👤 Yasuyuki Suzuki
- 👤 Masayuki Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:59
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5036; A61K9/5042; A61K9/5047; A61K47/00; A61K47/50; A61K47/51; A61K47/56; A61K47/58; A61K47/585; A61K9/5026
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
45 words
A sustained-release microcapsule preparation comprising: (a) an ion exchange resin which is about 6 to 16% cross-linked, (b) a drug adsorbed onto the ion exchange resin in an amount not less than 80% of its theoretical ion adsorption amount, and (c) a water-permeable polymer coating.
Claim 2
Dependent Claim
45 words
A sustained-release microcapsule preparation comprising: (a) an ion exchange resin which is about 6 to 16% cross-linked, (b) a drug adsorbed onto the ion exchange resin in an amount not less than 80% of its theoretical ion adsorption amount, and (c) a water-permeable polymer coating.
Claim 3
Dependent Claim
58 words
A method of producing the preparation according to claim 1, comprising adsorbing a drug in an amount not less than pb 80% of its theoretical ion adsorption amount onto an ion exchange resin which is about 6 to 16% cross-linked to form an ion exchange complex, and then coating the resulting ion exchange complex with a water-permeable polymer.
Claim 4
Dependent Claim
17 words
The preparation according to claim 1, wherein the ion exchange resin is a synthetic insoluble porous polymer.
Claim 5
Dependent Claim
16 words
The preparation according to claim 3, wherein the polymer is a copolymer of styrene and divinylbenzene.
Claim 6
Dependent Claim
17 words
The preparation according to claim 1, wherein the ion exchange resin is an acidic ion exchange resin.
Claim 7
Dependent Claim
25 words
The preparation according to claim 1, wherein the drug has a pKa from 6 to 10 or from 2 to 5 with a stericallybulky structure.
Claim 8
Dependent Claim
16 words
The preparation according to claim 1, wherein the drug is a drug for the respiratory tract.
Claim 9
Dependent Claim
19 words
The preparation according to claim 1, wherein the drug is a free form derived from the corresponding salt form.
Claim 10
Dependent Claim
14 words
The preparation according to claim 7, wherein the drug is dihydrocodeine, phenylpropanolamine or dl-methylephedrine.
Claim 11
Dependent Claim
26 words
The preparation according to claim 1, wherein the water-permeable polymer coating is a compound selected from the group consisting of polyacrylate, polymethacrylate, polyamide or acrylate-methacrylate copolymer.
Claim 12
Dependent Claim
20 words
The preparation according to claim 1, wherein the mean size of the microcapsule is from 5 to 1,000 ° m.
Claim 13
Dependent Claim
17 words
A suspension for oral administration containing the preparation according to claim 1 in suspension in purified water.
Claim 14
Dependent Claim
68 words
The method according to claim 2, wherein the drug-ion exchange resin complex is produced by adding an ion exchange resin which is about 6 to 16% crosslinked to an aqueous solution of a drug in a free form prepared by reacting a salt of the drug with an ion exchange resin in an aqueous solvent capable of dissolving both the salt and the free form of the drug.
References Cited (Backward Citations)
US2990332A
Cited
US3138525A
Cited
US3313686A
Cited
US3499960A
Cited
US3594470A
Cited
DE1908946A1
Cited
GB1218102A
Cited
DE2246037A1
Cited
US3904444A
Cited
US3992518A
Cited
US4221778A
Cited
US4548990A
Cited
EP0154009A1
Cited
US4711777A
Cited
US4668506A
Cited
US4794002A
Cited
EP0225615A2
Cited
US4741872A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |