Patent US4389331A successfully refreshed from Google Patents.
US4389331A
Expired / Lapsed
US
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Process for preparing pharmaceutically active compound-containing microcapsules
Assignee: Tanabe Pharma Corp
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Filing: 1980-10-07
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Granted: 1983-06-21
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Expires: 2000-10-07
Abstract
Abstract A process for preparing ethylcellulose microcapsules of a pharmaceutically active compound by phase separation-coacervation of the ethylcellulose is disclosed. In this process, phospholipids are used as a phase-separation-inducing agent.
Inventors
- 👤 Masayoshi Samejima
- 👤 Goichi Hirata
- 👤 Yoshiyuki Koida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:48
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5089; A61K9/5005; A61K9/5021; A61K9/5036; A61K9/5042; A61K9/5047; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
83 words
A process for preparing microcapsules containing a pharmaceutically active compound comprising: dissolving (a) about 0.02 to about 5 g per gram of said compound of ethylcellulose, and (b) about 0.0002 to about 1 g per gram of the total of said ethylcellulose plus said compound of phospholipids in cyclohexane, dispersing articles of the compound in said solution, cooling the dispersion under continuous stirring until the ethylcellulose separates out from the dispersion, thereby coating the particles of compound, and then recovering the microcapsules formed.
Claim 2
Dependent Claim
83 words
A process for preparing microcapsules containing a pharmaceutically active compound comprising: dissolving (a) about 0.02 to about 5 g per gram of said compound of ethylcellulose, and (b) about 0.0002 to about 1 g per gram of the total of said ethylcellulose plus said compound of phospholipids in cyclohexane, dispersing articles of the compound in said solution, cooling the dispersion under continuous stirring until the ethylcellulose separates out from the dispersion, thereby coating the particles of compound, and then recovering the microcapsules formed.
Claim 3
Dependent Claim
22 words
The process according to claim 1, wherein ethylcellulose having an ethoxy content of about 47.0 to about 51.0 w/w % is used.
Claim 4
Dependent Claim
25 words
The process according to claim 1 wherein the phospholipids are selected from the group consisting of soybean phospholipids, egg-yolk phospholipids, phosphatidyl cholin and phosphatidyl ethanolamine.
Claim 5
Dependent Claim
57 words
The process according to claim 2, 3, or 1 wherein the ethylcellulose and phospholipids are dissolved in cyclohexane at a temperature of about 75° to about 80° C., and the dispersion containing said pharmaceutically active compound is cooled gradually to a temperature not higher than 50° C. under conditions stirring at about 20 to about 600 rpm.
Claim 6
Dependent Claim
21 words
The process according to claim 4, wherein said dispersion is cooled at a rate of 0.05° to 5° C. per minute.
Claim 7
Dependent Claim
22 words
The process according to claim 4, wherein a pharmaceutically active compound having a particle size of not more than 1000μ is used.
Claim 8
Dependent Claim
41 words
The process according to claim 4, wherein the phospholipids are dissolved in cyclohexane at a concentration of about 0.01 to about 10 w/w %, and the ethylcellulose is dissolved therein at a concentration of about 0.5 to about 10 w/w %.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |