EP0239361A1
Expired / Lapsed
EP
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Sustained-release pharmaceutical preparation
Assignee: Kinaform Technology Inc
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Filing: 1987-03-24
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Granted: —
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Expires: 2007-03-24
Abstract
Abstract A sustained-release pharmaceutical preparation comprising an admixture of uncoated and/or single walled water soluble drug, such as aspirin, and dual walled coated drug. The dual wall structure has an inner wall microencapsular control coating, such as ethyl cellulose, and an outer wall enteric coating such as cellulose acetate phthalate. The dual walled coated drug has a delayed, gradual, long-term release which takes place in the intestines while the uncoated and/or single walled drug has immediate therapeutic properties upon dissolution in the stomach. The outer wall enteric coating may be applied to microencapsulated core drug by a coacervation, spray coating or other process.
Inventors
- 👤 Herman J. Eichel
- 👤 Brent D. Massmann
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 10:08
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5073; A61K9/5084; A61P; A61P25/00; A61P25/04
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
83 words
A sustained-release pharmaceutical preparation comprising an admixture of a) an uncoated or single walled water-soluble drug, and b) a dual walled coated medicament comprising a core of said drug coated with an inner wall microencapsular control coating which will not dissolve or disperse readily in the intestines, but which permits release of said drug through said inner microencapsular coating and an outer wall enteric coating which will not dissolve or dispense readily in the stomach, but which dissolves or disperses in the intestines.
Claim 2
Dependent Claim
83 words
A sustained-release pharmaceutical preparation comprising an admixture of a) an uncoated or single walled water-soluble drug, and b) a dual walled coated medicament comprising a core of said drug coated with an inner wall microencapsular control coating which will not dissolve or disperse readily in the intestines, but which permits release of said drug through said inner microencapsular coating and an outer wall enteric coating which will not dissolve or dispense readily in the stomach, but which dissolves or disperses in the intestines.
Claim 3
Dependent Claim
30 words
The sustained-release pharmaceutical preparation of claim 1 wherein said inner wall microencapsular control coating is selected from the group consisting of ethyl cellulose, hydroxy propyl cellulose, and carboxy methyl cellulose.
Claim 4
Dependent Claim
42 words
The sustained-release pharmaceutical preparation of claim 2 wherein said outer wall enteric coating is selected from the group consisting of cellulose acetate phthalate, hydroxypropyl methyl cellulose phthalate, polyvinyl acetate phthalate, hydroxyethyl ethyl cellulose phthalate, cellulose acetate tetrahydrophthalate, acrylic resin, shellac and wax.
Claim 5
Dependent Claim
25 words
The sustained-release pharmaceutical preparation of claim 3 wherein said drug is selected from the group consisting of aspirin, acetaminophen, dextromethorphan, hydrobromide, disopyramide phosphate and furosemide.
Claim 6
Dependent Claim
32 words
The sustained-release pharmaceutical preparation of claim 1 wherein said drug is granular aspirin, said inner wall microencapsular control coating is ethyl cellulose, and said outer wall enteric coating is cellulose acetate phthalate.
Claim 7
Dependent Claim
27 words
The sustained-release pharmaceutical preparation of claim 5 wherein the phase ratio of said granular aspirin to said outer wall enteric coating is from approximately 4:1 to 12:1.
Claim 8
Dependent Claim
35 words
The sustained-release pharmaceutical preparation of claim 5 wherein said uncoated aspirin is present in the amount of approximately 400-600 milligrams and said dual walled coated aspirin is present in the amount of approximately 400-600 milligrams.
Claim 9
Dependent Claim
35 words
The sustained-release pharmaceutical preparation of claim 5 wherein said uncoated aspirin is present in the amount of approximately 325-425 mg. and said dual walled coated aspirin is present in the amount of approximately 875-975 mg.
Claim 10
Dependent Claim
58 words
A dual walled coated medicament comprising: a core containing a water-soluble drug, an inner wall microencapsular control coating selected from the group consisting of ethyl cellulose, hydroxy propyl cellulose, and carboxy methyl cellulose, and an outer wall enteric coating selected from the group consisting of cellulose acetate phthalate, shellac, wax and phthalate or polyphthalate esters of film-forming polymers.
Claim 11
Dependent Claim
58 words
A dual walled coated medicament comprising: a core containing a water-soluble drug, an inner wall microencapsular control coating selected from the group consisting of ethyl cellulose, hydroxy propyl cellulose, and carboxy methyl cellulose, and an outer wall enteric coating selected from the group consisting of cellulose acetate phthalate, shellac, wax and phthalate or polyphthalate esters of film-forming polymers.
Claim 12
Dependent Claim
27 words
The dual walled coated medicament of claim 9 wherein said core drug is selected from the group consisting of aspirin, acetominophen, dextromethorphan hydrobromide, disopyramide phosphate and furosemide.
Claim 13
Dependent Claim
19 words
The dual walled coated medicament of claim 9 wherein said outer wall enteric coating is microencapsular cellulose acetate phthalate.
Claim 14
Dependent Claim
18 words
The dual walled coated medicament of claim 11 wherein said inner wall microencapsular control coating is ethyl cellulose.
Claim 15
Dependent Claim
51 words
The dual walled coated medicament of claim 12 wherein the phase ratio of said microencapsular coated core drug to said outer wall enteric coating is from approximately 4:1 to 30:1 and the phase ratio of said core drug to said inner wall microencapsular control coating is from approximately 2:1 to 30:1.
Claim 16
Dependent Claim
34 words
The dual walled coated medicament of claim 13 wherein said core drug is granular aspirin, said inner wall microencapsular control coating is ethyl cellulose, said outer wall enteric coating is microencapsular cellulose acetate phthalate.
Claim 17
Independent Claim
81 words
A method for preparing a sustained-release pharmaceutical preparation comprising: a) adding ethyl cellulose encapsulated aspirin to a solution containing dissolved cellulose acetate phthalate, b) adding a phase separation inducing agent whereby coacervation occurs and produces a dual walled coated aspirin having an ethyl cellulose inner wall and a cellulose acetate phthalate outer wall, c) hardening said cellulose acetate phthalate outer wall, d) washing and drying said dual walled coated aspirin, and e) admixing said dual walled coated aspirin with uncoated aspirin.
Claim 18
Independent Claim
81 words
A method for preparing a sustained-release pharmaceutical preparation comprising: a) adding ethyl cellulose encapsulated aspirin to a solution containing dissolved cellulose acetate phthalate, b) adding a phase separation inducing agent whereby coacervation occurs and produces a dual walled coated aspirin having an ethyl cellulose inner wall and a cellulose acetate phthalate outer wall, c) hardening said cellulose acetate phthalate outer wall, d) washing and drying said dual walled coated aspirin, and e) admixing said dual walled coated aspirin with uncoated aspirin.
Claim 19
Dependent Claim
20 words
The method of claim 15 wherein said cellulose acetate phthalate containing solution is buffered at a pH greater than 5.5.
Claim 20
Dependent Claim
16 words
The method of claim 16 wherein said phase separation inducing agent is 10-40% aqueous sodium sulfate.
Claim 21
Dependent Claim
11 words
The method of claim 17 wherein said hardener is acetic acid.
Claim 22
Dependent Claim
18 words
The method of claim 18 wherein said pH is reduced to below 4 on addition of said hardener.
References Cited (Backward Citations)
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