Patent US4244941A successfully refreshed from Google Patents.
US4244941A
Expired / Lapsed
US
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Controlled release composition and process for preparing same
Assignee: Gist Brocades NV
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Filing: 1975-10-23
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Granted: 1981-01-13
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Expires: 1995-10-23
Abstract
Abstract Solid constant release composition wherein (a) the solution of soluble core substance within the core space remains saturated during dissolution and (b) the shape and (c) the surface of the coating and (d) the diffusion path for the soluble core substance through the porous coating remains constant while the composition is in a liquid medium, which composition is very useful in media in which constant release during substantially the whole release period is desired, for example, for medical, chemical and fermentation purposes.
Inventors
- 👤 Coenraad F. Lerk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:07
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/28; A61K9/2806; A61K9/2833; A61K9/2853; A61K9/2813; A61K9/284
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
122 words
A constant release composition wherein (a) the solution of soluble core substance within the core space remains saturated during dissolution and (b) the shape and (c) the surface of the coating and (d) the diffusion path for the soluble core substance through the porous coating remain constant while the composition is in a liquid medium, comprising a core of the soluble substance and a rigid porous coating completely surrounding the core and which coating is substantially free of substances which are soluble or swellable in the liquid medium, said coating substance being selected from substances insoluble in the medium in which they are intended to be used and having been compressed in powder form to form an inert, non-disintegrating non-eroding porous coating.
Claim 2
Dependent Claim
122 words
A constant release composition wherein (a) the solution of soluble core substance within the core space remains saturated during dissolution and (b) the shape and (c) the surface of the coating and (d) the diffusion path for the soluble core substance through the porous coating remain constant while the composition is in a liquid medium, comprising a core of the soluble substance and a rigid porous coating completely surrounding the core and which coating is substantially free of substances which are soluble or swellable in the liquid medium, said coating substance being selected from substances insoluble in the medium in which they are intended to be used and having been compressed in powder form to form an inert, non-disintegrating non-eroding porous coating.
Claim 3
Dependent Claim
13 words
A composition of claim 1 wherein the soluble core substance contains a medicament.
Claim 4
Dependent Claim
16 words
A composition of claim 1 wherein the soluble core substance contains a reagent for chemical processes.
Claim 5
Dependent Claim
18 words
A composition of claim 1 wherein the soluble core substance contains a physiologically active substance for microbiological processes.
Claim 6
Dependent Claim
37 words
A composition of claim 1 wherein the coating substance is a polymer selected from the group consisting of a copolymer of vinyl chloride and vinyl acetate, a copolymer of vinylidene chloride and acrylonitrile, polyethylene, polymethylmethacrylate and polystyrene.
Claim 7
Dependent Claim
28 words
A composition of claim 1 wherein the coating substance is an inorganic substance selected from the group consisting of dicalcium phosphate dihydrate, tricalcium phosphate and anhydrous calcium sulfate.
Claim 8
Dependent Claim
30 words
The composition of claim 1 wherein the soluble core substance is selected from the group consisting of potassium chloride, orphenadrine HCl, ephedrine HCl, sodium pentobarbital, procaine HCl, sulfanilamide and glucose.
Claim 9
Dependent Claim
34 words
A process for preparing a composition of claim 1 comprising dry mixing the components for the coating in the usual way, and coating the mixture so obtained completely around a core of soluble substance.
Claim 10
Dependent Claim
14 words
The process of claim 8 wherein the coating is applied in a tabletting machine.
Claim 11
Dependent Claim
26 words
The process of claim 8 wherein the coating is applied around the soluble core with a compression pressure of about 500 to 5000 kg/cm 2 .
Claim 12
Dependent Claim
15 words
The process of claim 10 wherein the pressure is 800 to 2500 kg/cm 2 .
Claim 13
Dependent Claim
13 words
The process of claim 8 wherein the soluble core substance contains a medicine.
Claim 14
Dependent Claim
16 words
The process of claim 8 wherein the soluble core substance contains a reagent for chemical processes.
Claim 15
Dependent Claim
18 words
The process of claim 8 wherein the soluble core substance contains a physiologically active substance for microbiological processes.
Claim 16
Dependent Claim
37 words
The process of claim 8 wherein the coating substance is a polymer selected from the group consisting of a copolymer of vinyl chloride and vinyl acetate, a copolymer of vinylidene chloride and acrylonitrile, polyethylene, polymethylmethacrylate and polystyrene.
Claim 17
Dependent Claim
28 words
The process of claim 8 wherein the coating substance is an inorganic substance selected from the group consisting of dicalcium phosphate dihydrate, tricalcium phosphate and anhydrous calcium sulfate.
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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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |