US4411933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing ethylcellulose microcapsules
Assignee: Tanabe Pharma Corp
•
Filing: 1981-04-09
•
Granted: 1983-10-25
•
Expires: 2001-04-09
Abstract
Abstract A process for preparing ethylcellulose microcapsules by flocculation of the ethylcellulose is disclosed. In this process, the flocculation of the ethylcellulose is carried out in the presence of an organosilicon polymer or in the presence of said organosilicon polymer and a surfactant.
Inventors
- 👤 Masayoshi Samejima
- 👤 Goichi Hirata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:45
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/10; A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5036; A61K9/5042; A61K9/5047; A61K9/5089; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2989
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
113 words
In a process for preparing ethylcellulose microcapsules comprising the steps of (i) dissolving ethylcellulose in cyclohexane, (ii) dispersing particles of a core material in said solution, (iii) cooling the dispersion until the ethylcellulose separates out from the dispersion to form coating walls on and around the particles of said core material, and then (iv) recovering the thus-formed ethylcellulose microcapsules therefrom, the improvement wherein an organosilicon polymer is dissolved in said cyclohexane in said step (i) in an amount of 0.1 to 10 w/v %, said organosilicon polymer having a viscosity of 50 to 5 million centistokes at 25° C. and said ethylcellulose being present in an amount of 0.1 to 10 w/v %.
Claim 2
Dependent Claim
113 words
In a process for preparing ethylcellulose microcapsules comprising the steps of (i) dissolving ethylcellulose in cyclohexane, (ii) dispersing particles of a core material in said solution, (iii) cooling the dispersion until the ethylcellulose separates out from the dispersion to form coating walls on and around the particles of said core material, and then (iv) recovering the thus-formed ethylcellulose microcapsules therefrom, the improvement wherein an organosilicon polymer is dissolved in said cyclohexane in said step (i) in an amount of 0.1 to 10 w/v %, said organosilicon polymer having a viscosity of 50 to 5 million centistokes at 25° C. and said ethylcellulose being present in an amount of 0.1 to 10 w/v %.
Claim 3
Dependent Claim
23 words
The process according to claim 1 wherein said organosilicon polymer has a viscosity of about 100 to about 2,000,000 centistokes at 25° C.
Claim 4
Dependent Claim
32 words
The process according to claim 1 wherein the organosilicon polymer is selected from the group consisting of di(lower alkyl)polysiloxane, lower alkyl phenyl polysiloxane, diphenyl polysiloxane, silicone-glycol copolymer and polystyrenepolydi(lower alkyl)siloxane block copolymer.
Claim 5
Dependent Claim
28 words
The process according to claim 1 wherein the organosilicon polymer is selected from the group consisting of dimethyl polysiloxane, methyl phenyl polysiloxane, silicone-glycol copolymer and polystyrene-polydimethylsiloxane block copolymer.
Claim 6
Dependent Claim
26 words
The process according to any one of claims 2-4 or 1 wherein said ethylcellulose has an ethoxy content of about 47 to about 55 w/w %.
Claim 7
Dependent Claim
22 words
The process according to any one of claims 2-4 or 1 wherein the organosilicon polymer is used in combination with a surfactant.
Claim 8
Dependent Claim
27 words
The process according to claim 6 wherein the surfactant is present in an amount of about 0.001 to about 10 grams per gram of the organosilicon polymer.
Claim 9
Dependent Claim
21 words
The process according to claim 6 wherein said ethylcellulose has an ethoxy content of about 47 to about 55 w/w %.
Claim 10
Dependent Claim
62 words
The process according to any one of claims 2-4 or 1 wherein the ethylcellulose and the organosilicon polymer are dissolved in cyclohexane at a temperature of about 75° to about 80° C., and the dispersion containing the core material is cooled gradually to a temperature not higher than 40° C. at a rate of about 0.05 to about 4° C. per minute.
Claim 11
Dependent Claim
21 words
The process according to claim 9 wherein said ethylcellulose has an ethoxy content of about 47 to about 55 w/w %.
Claim 12
Dependent Claim
29 words
The process according to any one of claims 2-4 or 1 wherein the core material is a pharmaceutically active compound having a particle size of not more than 1,000μ.
Claim 13
Dependent Claim
21 words
The process according to claim 11 wherein said ethylcellulose has an ethoxy content of about 47 to about 55 w/w %.
Claim 14
Dependent Claim
59 words
The process according to claim 6 wherein the ethylcellulose, the organosilicon polymer, and the surfactant are dissolved in cyclohexane at a temperature of about 75° to about 80° C., and the dispersion containing the core material is cooled gradually to a temperature not higher than 40° C. at a rate of about 0.05 to about 4° C. per minute.
Claim 15
Dependent Claim
21 words
The process according to claim 13 wherein said ethylcellulose has an ethoxy content of about 47 to about 55 w/w %.
Claim 16
Dependent Claim
27 words
The process according to claim 13 wherein the surfactant is present in an amount of about 0.001 to about 10 grams per gram of the organosilicon polymer.
References Cited (Backward Citations)
US3415758A
Cited
US3155590A
Cited
US3341416A
Cited
US3531418A
Cited
US3943063A
Cited
US4218333A
Cited
US4220552A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |