US4678516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sustained release dosage form based on highly plasticized cellulose ether gels
Assignee: Dow Chemical Co
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Filing: 1984-10-09
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Granted: 1987-07-07
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Expires: 2004-10-09
Abstract
Abstract A solid sustained release dosage form is disclosed comprising a gel matrix containing HPMC and a major amount of a plasticizer therefor into which gel matrix is reversibly dispersed a pharmaceutically active agent.
Inventors
- 👤 Daniel A. Alderman
- 👤 Troy D. Wolford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:47
CPC Classifications
A; A61; A61K; A61K47/00; A61K47/30; A61K47/36; A61K47/38; A61K9/00; A61K9/0012; A61K9/0014; A61K9/70; A61K9/7023; Y; Y10; Y10S; Y10S424/00; Y10S424/14; Y10S424/15
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
59 words
A thermoformable sustained release matrix for the prolonged release of an active organic material, which matrix comprises (a) a thermoplastic water-soluble gel comprising a water-soluble hydroxypropyl methylcellulose homogeneously dispersed in an amount of a plasticizer for the cellulose ether sufficient to render the matrix thermoformable, and (b) dispersed in said gel, an effective amount of an active organic material.
Claim 2
Dependent Claim
59 words
A thermoformable sustained release matrix for the prolonged release of an active organic material, which matrix comprises (a) a thermoplastic water-soluble gel comprising a water-soluble hydroxypropyl methylcellulose homogeneously dispersed in an amount of a plasticizer for the cellulose ether sufficient to render the matrix thermoformable, and (b) dispersed in said gel, an effective amount of an active organic material.
Claim 3
Dependent Claim
19 words
The matrix of claim 1 wherein said plasticizer is a solvent for said hydroxypropyl methylcellulose at an elevated temperature.
Claim 4
Dependent Claim
28 words
The matrix of claim 2 wherein said active organic material is not rendered inactive at an elevated temperature in which the hydroxypropyl methylcellulose is soluble in said plasticizer.
Claim 5
Dependent Claim
32 words
The sustained release matrix of claim 2 wherein said hydroxypropyl methylcellulose has a hydroxypropoxyl molar substitution from about 0.05 to 3.0 and a methoxyl degree of substitution for about 0.8 to 2.5.
Claim 6
Dependent Claim
30 words
The matrix of claim 4 wherein said hydroxypropyl methylcellulose has a hydroxypropoxyl molar substitution for about 0.2 to 0.31 and a methoxyl degree of substitution from about 1.8 to 2.0.
Claim 7
Dependent Claim
30 words
The matrix of claim 4 wherein said hydroxypropyl methylcellulose has a hydroxypropoxyl molar substitution for about 0.1 to 0.3 and a methoxyl degree of substitution from about 1.1 to 1.6.
Claim 8
Dependent Claim
30 words
The matrix of claim 4 wherein said hydroxypropyl methylcellulose has a hydroxypropoxyl molar substitution for about 0.7 to 1.0 and a methoxyl degree of substitution from about 1.1 to 1.6.
Claim 9
Dependent Claim
26 words
The matrix of claim 2 wherein said plasticizer is ethylene glycol, a low molecular weight polyethylene glycol, propylene glycol or a low molecular weight propropylene glycol.
Claim 10
Dependent Claim
13 words
The matrix of claim 4 wherein the active organic material is a pharmaceutical.
Claim 11
Dependent Claim
11 words
The matrix of claim 9 which is an oral dosage unit.
Claim 12
Dependent Claim
10 words
The matrix of claim 4 which is a rectal suppository.
Claim 13
Dependent Claim
12 words
The dosage form of claim 4 which is a intravaginal dosage form.
Claim 14
Dependent Claim
12 words
The matrix of claim 4 wherein the active agent is an antimicrobial.
Claim 15
Dependent Claim
26 words
The sustained release matrix of claim 1, wherein the plasticizer comprises from about 30 to 95 percent of the combined weight of plasticizer and hydroxypropyl methylcellulose.
References Cited (Backward Citations)
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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) | 1990-07-06 | 1991-01-05 | 1991-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-06 | 1995-01-05 | 1995-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-06 | 1999-01-05 | 1999-07-07 | $7700.00 | Window Closed / Lapsed |