US5068112A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled release pharmaceutical preparation and method for producing the same
Assignee: Tanabe Pharma Corp
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Filing: 1989-03-24
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Granted: 1991-11-26
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Expires: 2009-03-24
Abstract
Abstract Disclosed is a controlled release pharmaceutical preparation, comprising a core containing a pharmaceutically active ingredient, and a porous film of a hydrophobic polymeric substance or a hydrophobic polymeric substance and a hydrophilic polymeric substance, the core being coated with the porous film. Disclosed is also a method for producing the same. The controlled release pharmaceutical preparation of this invention posseses a desired dissolution rate by controlling the porosity of the porous film.
Inventors
- 👤 Masayoshi Samejima
- 👤 Kazuo Noda
- 👤 Yoshiyuki Hirakawa
- 👤 Hiroyuki Yoshino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:23
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/14; A61K9/16; A61K9/48; A61K9/50; A61K9/5073; A61K9/5078; A61K9/20; A61K9/28; A61K9/2806; A61K9/2833; A61K9/286; A61K9/2866
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
66 words
A controlled release pharmaceutical preparation comprising: (A) a core containing a pharmaceutically active ingredient and succinic acid; and (B) a porous cellulose film formed on the surface of said core by spraying a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula: ##EQU2##
Claim 2
Dependent Claim
66 words
A controlled release pharmaceutical preparation comprising: (A) a core containing a pharmaceutically active ingredient and succinic acid; and (B) a porous cellulose film formed on the surface of said core by spraying a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula: ##EQU2##
Claim 3
Dependent Claim
18 words
The preparation according to claim 1, wherein said porous film has a porosity of about 0.5 to 0.85.
Claim 4
Dependent Claim
13 words
The preparation according to claim 1, wherein said porous film comprises ethyl cellulose.
Claim 5
Dependent Claim
16 words
The preparation according to claim 1, wherein said porous film comprises ethyl cellulose and hydroxypropyl cellulose.
Claim 6
Dependent Claim
30 words
The preparation according to claim 4, wherein said porous film comprises 0.05 to 0.5 part by weight of said hydroxypropyl cellulose per 1 part by weight of said ethyl cellulose.
Claim 7
Independent Claim
69 words
A method of producing a controlled release pharmaceutical preparation which comprises spray-coating a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose onto the surface of a core containing a pharmaceutically active ingredient and succinic acid to produce a porous cellulose film on said core, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula: ##EQU3##
Claim 8
Independent Claim
69 words
A method of producing a controlled release pharmaceutical preparation which comprises spray-coating a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose onto the surface of a core containing a pharmaceutically active ingredient and succinic acid to produce a porous cellulose film on said core, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula: ##EQU3##
References Cited (Backward Citations)
EP0148811A1
Cited
US4666702A
Cited
US4769027A
Cited
US4629619A
Cited
US4663147A
Cited
US4832958A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-25 | 1995-05-27 | 1995-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-25 | 1999-05-27 | 1999-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-25 | 2003-05-27 | 2003-11-26 | $7700.00 | Window Closed / Lapsed |