Patent US4606940A successfully refreshed from Google Patents.
US4606940A
Expired / Lapsed
US
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Small particle formation and encapsulation
Assignee: Ohio State University Research Foundation
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Filing: 1984-12-21
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Granted: 1986-08-19
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Expires: 2004-12-21
Abstract
Abstract Process for the formation and the simultaneous encapsulation of small particles of a compound from solution which comprises: (a) dissolving said compound in a first solvent; (b) preparing a solution of encapsulating material and an electrolyte in a second solvent which is miscible with the first solvent and in which the compound to be encapsulated is more or less insoluble, in an amount which is effective, but present in an amount just insufficient to cause coacervation of the encapsulating material without interacting with it; (c) mixing the solutions from step (a) and (b) while stirring to cause the concurrent precipitation of the compound as small particles and formation of a coacervate of the encapsulating material; and (d) gelling the encapsulating material.
Inventors
- 👤 Sylvan G. Frank
- 👤 Arne F. Brodin
- 👤 Shulin Ding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:50
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5073; A61K9/14; A61K9/16; A61K9/1682; A61K9/1694; A61K9/5089; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A process for encapsulating an organic compound whose solubility is greater in a first solvent than in a second solvent which process comprises: (a) dissolving said compound in a first solvent; (b) preparing a solution of encapsulating material and an electrolyte in a second solvent which is miscible with the first solvent and in which the compound to be encapsulated is more or less insoluble, in an amount which is effective, but which electrolyte is present in an amount just insufficient to cause coacervation of the encapsulating material without interacting with it; (c) mixing the solutions from step (a) and (b) while stirring to cause the concurrent precipitation of the compound as small particles and formation of a coacervate of the encapsulating material; and (d) gelling the encapsulating material.
Claim 2
Dependent Claim
129 words
A process for encapsulating an organic compound whose solubility is greater in a first solvent than in a second solvent which process comprises: (a) dissolving said compound in a first solvent; (b) preparing a solution of encapsulating material and an electrolyte in a second solvent which is miscible with the first solvent and in which the compound to be encapsulated is more or less insoluble, in an amount which is effective, but which electrolyte is present in an amount just insufficient to cause coacervation of the encapsulating material without interacting with it; (c) mixing the solutions from step (a) and (b) while stirring to cause the concurrent precipitation of the compound as small particles and formation of a coacervate of the encapsulating material; and (d) gelling the encapsulating material.
Claim 3
Dependent Claim
12 words
A process according to claim 1 wherein the encapsulated material is hardened.
Claim 4
Dependent Claim
22 words
A process according to claim 1 wherein the encapsulated material is redispersed in a liquid and encapsulated in a different encapsulating material.
Claim 5
Dependent Claim
33 words
A process according to claim 1 wherein additional electrolyte is added after step (b) to cause concurrent precipitation of the compound as small particles and formation of a coacervate of the encapsulating material.
Claim 6
Dependent Claim
12 words
A process according to claim 1 wherein the compound is pharmaceutically active.
Claim 7
Dependent Claim
21 words
A process according to claim 5, wherein the pharmaceutically active compound is selected from the group consisting of budesonide and felodipine.
Claim 8
Dependent Claim
15 words
A process according to claim 1 wherein a wetting agent is used in step a.
Claim 9
Dependent Claim
16 words
A process according to claim 1 wherein, if needed, the temperature is controlled in step c.
Claim 10
Dependent Claim
20 words
A process according to claim 8, wherein the ratio of encapsulating material to wetting agent to electrolyte is about (0.1-6):(0.1-4):(0.1-10):(0.4-48).
Claim 11
Dependent Claim
29 words
A process according to claim 1, wherein the encapsulating material is selected from the group consisting of gelatin, methylcellulose, hydroxypropyl methylcellulose, sodium carboxymethylcellulose, cellulose acetate phthalate, ethylcellulose, and polyvinylpyrrolidone.
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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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |