EP0126537A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Sustained release capsule and process of making it
Assignee: Abbott Biotech Inc
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Filing: 1984-04-06
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Granted: —
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Expires: 2004-04-06
Abstract
Abstract A dispensing system for the sustained releasing of a substance at a substantially constant rate includes semipermeable capsules containing a material to be released. The capsules comprise membranes having pores of dimensions sufficient to control the kinetics of release provided there is maintained a large intracapsular concentration of the substance relative to the concentration desired in the extracapsular environment. The system may be produced by forming permeable capsules, suspending the capsules in a solution containing a high concentration of the substance to load the intracapsular volume, and then post-treating the capsules to reduce the size of the pores.
Inventors
- 👤 Franklin Lim
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 02:03
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1652; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5026; A61K9/5031
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
96 words
A dispensing system for releasing a substance at a substantially constant rate in an environment that depletes said substance, said system comprising: a capsule having a membrane which defines an intracapsular volume, said membrane having a multiplicity of pores of dimensions sufficient to limit the rate of which the molecules of said substance pass therethrough from said intracapsular volume; and disposed within said volume, a liquid reservoir of said substance at a concentration of said substance which results in an osmotic pressure sufficient to sustain said limited rate when said capsule is placed in said environment.
Claim 2
Dependent Claim
96 words
A dispensing system for releasing a substance at a substantially constant rate in an environment that depletes said substance, said system comprising: a capsule having a membrane which defines an intracapsular volume, said membrane having a multiplicity of pores of dimensions sufficient to limit the rate of which the molecules of said substance pass therethrough from said intracapsular volume; and disposed within said volume, a liquid reservoir of said substance at a concentration of said substance which results in an osmotic pressure sufficient to sustain said limited rate when said capsule is placed in said environment.
Claim 3
Dependent Claim
41 words
The system of claim 1 for purposes of maintaining a given extracapsular concentration in said environment wherein the reservoir of said substance within said intracapsular volume is at a concentration at least two orders of magnitude greater than said given concentration.
Claim 4
Dependent Claim
22 words
The system of claim 1 wherein said substance is a solid disposed within said intracapsular volume in a solvent for said solid.
Claim 5
Dependent Claim
14 words
The system of claim 3 wherein said solid is sparingly soluble in said solvent.
Claim 6
Dependent Claim
13 words
The system of claim 1 wherein said substance comprises a biologically active material.
Claim 7
Dependent Claim
24 words
The system of claim 5 wherein said biologically active material is selected from the group consisting of hormones, enzymes, antibodies, vaccines, drugs, and lymphokines.
Claim 8
Dependent Claim
22 words
The system of claim 1 wherein said substance is selected from the group consisting of plant fertilizers, pesticides, fungicides, and plant hormones.
Claim 9
Dependent Claim
19 words
The system of claim 1 wherein said substance is selected from the group consisting of flavors, perfumes, and preservatives.
Claim 10
Dependent Claim
13 words
The system of claim 1 wherein said substance is a tissue culture nutrient.
Claim 11
Dependent Claim
37 words
The system of claim 1 further comprising, for storage purposes, an extracapsular volume of said substance at a concentration sufficient to substantially prohibit a net flow of said substance from said intracapsular volume to said extracapsular volume.
Claim 12
Dependent Claim
20 words
The system of claim 1 wherein said membrane comprises a matrix of polycationic polymer salt bonded to a polyanionic polymer.
Claim 13
Dependent Claim
20 words
The system of claim 1 wherein said membrane defines a sphere having a diameter between about 0.1 and 3.0 mm.
Claim 14
Dependent Claim
114 words
A process for producing the dispensing system of claim 1 comprising the steps of:- A. forming a capsule which defines an intracapsular volume and comprises a membrane defining a multiplicity of pores of a size sufficient to permit passage of molecules of said substance; B. placing said capsule in a solution containing a concentration of said substance for a time sufficient to permit said solution and said substance to diffuse into said intracapsular volume to produce a capsule loaded with said substance; and C. reducing the dimensions of the pores defined by the membrane of said loaded capsule to a degree sufficient to limit the rate at which molecules of said substance pass therethrough.
Claim 15
Dependent Claim
59 words
The process of claim 13 wherein step A comprises the steps of:- 1) forming a shape-retaining sphere comprising a water-soluble polymer comprising plural cationic or anionic groups; and 2) contacting said sphere with a first polymer comprising plural groups having a charge opposite that of said water-soluble polymer to produce a capsule comprising a porous membrane about said sphere.
Claim 16
Dependent Claim
46 words
The process of claim 13 wherein, in step A, the dimensions of said pores are controlled such that passage of the molecules of said substance is hindered and in step B, the rate of diffusion of said substance into said capsule is controlled by said membrane.
Claim 17
Independent Claim
44 words
A method of producing a system for releasing a substance at a predetermined rate comprising forming a permeable capsule, suspending the capsule in a solution containing the substance thereby to load the substance into the capsule, and post-treating the capsule to reduce its permeability.
Claim 18
Independent Claim
44 words
A method of producing a system for releasing a substance at a predetermined rate comprising forming a permeable capsule, suspending the capsule in a solution containing the substance thereby to load the substance into the capsule, and post-treating the capsule to reduce its permeability.
References Cited (Backward Citations)
No citation records indexed.
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