US5523095A
Expired / Lapsed
US
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Controlled release matrix system using cellulose acetate/polyvinylpyrrolidone blends
Assignee: Eastman Chemical Co
•
Filing: 1993-12-15
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Granted: 1996-06-04
•
Expires: 2013-12-15
Abstract
Abstract This invention relates to a controlled release matrix system comprising a homogenous mixture of polyvinylpyrrolidone, cellulose acetate having a degree of substitution for acetyl of from about 0.5 to 3.0, and a water-soluble active ingredient.
Inventors
- 👤 Alan K. Wilson
- 👤 Jessica Posey-Dowty
- 👤 Stephen S. Kelley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:12
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/70; A61K9/7007; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
110 words
A controlled release matrix system comprising a homogenous mixture of polyvinylpyrrolidone and cellulose acetate having a degree of substitution for acetyl of from 0.5 to 3.0, and of a water-soluble active ingredient, wherein said cellulose acetate is present in the amount of 95 to 20 weight % and the polyvinylpyrrolidone is present in the amount of 5 to 80 weight %, based on the total weight percentages of the plyvinylpyrrolidone and cellulose acetate equalling 100 weight %, and wherein said active ingredient is present in the amount of 0.01 to 40 weight % based on the total weight percentages of polyvinylpyrrolidone, cellulose aceate and active ingredient equalling 100 weight %.
Claim 2
Dependent Claim
110 words
A controlled release matrix system comprising a homogenous mixture of polyvinylpyrrolidone and cellulose acetate having a degree of substitution for acetyl of from 0.5 to 3.0, and of a water-soluble active ingredient, wherein said cellulose acetate is present in the amount of 95 to 20 weight % and the polyvinylpyrrolidone is present in the amount of 5 to 80 weight %, based on the total weight percentages of the plyvinylpyrrolidone and cellulose acetate equalling 100 weight %, and wherein said active ingredient is present in the amount of 0.01 to 40 weight % based on the total weight percentages of polyvinylpyrrolidone, cellulose aceate and active ingredient equalling 100 weight %.
Claim 3
Dependent Claim
18 words
The matrix system of claim 1 wherein said degree of substitution for acetyl is from 2.0 to 2.7.
Claim 4
Dependent Claim
18 words
The matrix system of claim 2 wherein said degree of substitution for acetyl is from 2.4 to 2.55.
Claim 5
Dependent Claim
51 words
The matrix system of claim 1 wherein said polyvinylpyrrolidone is present in an amount of 15 to 50 weight % and said cellulose acetate is present in an amount of 85 to 50 weight %, based the total weight percentages of said polyvinylpyrrolidone and said cellulose acetate equalling 100 weight %.
Claim 6
Dependent Claim
39 words
The matrix system of claim 1 wherein said active ingredient is present in the amount of 0.5 to 20 weight % based on the total weight percentages of said polyvinylpyrrolidone, cellulose acetate and active ingredient equalling 100 weight %.
Claim 7
Dependent Claim
14 words
The matrix system of claim 1 wherein said active ingredient is a pharmaceutical agent.
Claim 8
Dependent Claim
37 words
The matrix system of claim 6 wherein said pharmaceutical agent is selected from the group consisting of analgesics, anti-inflammatory agents, antibiotics, anti-depressants, anti-epileptics, anti-hypertensive agents, anti-arrhythmics, corticosteroids, lipid regulating agents, antacids, laxatives, anti-ulcer agents and mixtures thereof.
Claim 9
Dependent Claim
22 words
The matrix system of claim 7 wherein said pharmaceutical agent is selected from the group consisting of dextromethorphan-hydrobromide, acetaminophen, and acetylsalicylic acid.
Claim 10
Dependent Claim
13 words
The matrix system of claim 1 wherein said active ingredient is a pesticide.
Claim 11
Dependent Claim
9 words
The matrix system of claim 1 further comprising additives.
Claim 12
Dependent Claim
23 words
The matrix system of claim 10 wherein said additives are selected from the group consisting of fillers, lubricants, stabilizers, plasticizers and/or coloring agents.
Claim 13
Dependent Claim
27 words
The matrix system of claim 11 wherein said lubricants are selected from the group consisting of aluminum stearate, calcium stearate, magnesium stearate, tin stearate talc, and silicones.
Claim 14
Dependent Claim
18 words
The matrix system of claim 12 wherein said lubricants are present in the amount of 0.1-5 weight %.
Claim 15
Dependent Claim
41 words
The matrix system of claim 11 wherein said plasticizers are selected from the group consisting of polyethylene glycols, plypropylene glycols, polyethylene-propylene glycols, glycerol, glycerol monoacetate, glycerol diacetate, glycerol triacetate, propylene glycol, sorbitol, sodium diethylsulfosuccinate, triethyl citrate, tributyl citrate and deithyl phthalate.
Claim 16
Dependent Claim
21 words
The matrix system of claim 14 wherein said plasticizers are present in concentrations ranging from about 0.5 to 15 weight %.
Claim 17
Dependent Claim
25 words
The matrix system of claim 15 in concentrations ranging from about 0.5 to 5 weight % based on the weight of all of the components.
Claim 18
Dependent Claim
18 words
The matrix system of claim 11 wherein said coloring agents comprise azo dyes, and organic or inorganic pigments.
Claim 19
Dependent Claim
26 words
The matrix system of claim 17 wherein said inorganic pigments are selected from the group consisting of the oxides of iron and the oxides of titanium.
Claim 20
Dependent Claim
29 words
The matrix system of claim 18 wherein said inorganic pigments are present in the amount of about 0.001 to 10 weight %, based on the weight of all components.
Claim 21
Dependent Claim
26 words
The matrix system of claim 11 wherein said fillers are inorganic and are selected from the group consisting of oxides of magnesium, aluminum, silicon, and titanium.
Claim 22
Dependent Claim
29 words
The matrix system of claim 20 wherein said inorganic fillers are present in the amount of about 0.02 to 3 weight % based on the weight of all components.
Claim 23
Dependent Claim
29 words
The matrix system of claim 21 wherein said inorganic fillers are present in the amount of about 0.2 to 1 weight % based on the weight of all components.
Claim 24
Dependent Claim
9 words
The matrix system of claim 1 compressed into tablets.
Claim 25
Dependent Claim
9 words
The matrix system of claim 1 comprising a pellet.
Claim 26
Dependent Claim
11 words
The matrix system of claim 1 made into a microporous film.
Claim 27
Dependent Claim
29 words
A method for the preparation of a matrix control release vehicle comprising the step of blending into a homogeneous mixture the components of the matrix system of claim 1.
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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) | 1999-06-04 | 1999-12-04 | 2000-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-04 | 2003-12-04 | 2004-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-04 | 2007-12-04 | 2008-06-04 | $7700.00 | Window Closed / Lapsed |