US4357312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making prolonged release body
Assignee: Boston Children's Hospital
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Filing: 1981-07-16
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Granted: 1982-11-02
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Expires: 2001-07-16
Abstract
Abstract In a method of making a biologically compatible, water-insoluble polymeric body for the controlled, prolonged release of a biologically active substance to a surrounding aqueous environment, the method including forming a liquid mixture containing the polymer, the active substance, and an organic solvent capable of dissolving the polymer, and solidifying the liquid mixture to form the polymeric body, the improvement wherein the liquid mixture further comprises water, the solidification is carried out by cooling the liquid mixture to a temperature sufficiently low to cause the water in the mixture to freeze, thereby creating channels in the body for the release of the active substance therefrom, and removing the organic solvent and the water from the body.
Inventors
- 👤 Dean S. T. Hsieh
- 👤 Robert S. Langer, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:59
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
139 words
In a method of making a biologically compatible, implantable water-insoluble polymeric body for the controlled, prolonged release of a biologically active substance to a surrounding aqueous environment, said method comprising forming a liquid mixture containing said polymer, said active substance, and an organic solvent capable of dissolving said polymer, and solidifying said liquid mixture to form said polymeric body, the improvement wherein said liquid mixture further comprises water, and said organic solvent is immiscible with water, so that said mixture is an emulsion said solidification is carried out by cooling said liquid mixture to a temperature sufficiently low to cause the water in said mixture to freeze, thereby creating channels in said body for the release of said active substance therefrom, and said method further includes the steps of removing said organic solvent and said water from said body.
Claim 2
Dependent Claim
139 words
In a method of making a biologically compatible, implantable water-insoluble polymeric body for the controlled, prolonged release of a biologically active substance to a surrounding aqueous environment, said method comprising forming a liquid mixture containing said polymer, said active substance, and an organic solvent capable of dissolving said polymer, and solidifying said liquid mixture to form said polymeric body, the improvement wherein said liquid mixture further comprises water, and said organic solvent is immiscible with water, so that said mixture is an emulsion said solidification is carried out by cooling said liquid mixture to a temperature sufficiently low to cause the water in said mixture to freeze, thereby creating channels in said body for the release of said active substance therefrom, and said method further includes the steps of removing said organic solvent and said water from said body.
Claim 3
Dependent Claim
25 words
In the method of claim 1, the improvement wherein said removing of said solvent and water is facilitated by subjecting said body to reduced pressure.
Claim 4
Dependent Claim
47 words
In the method of claim 1, the improvement wherein said polymer is an ethylene-vinyl ester copolymer of the general formula: ##STR3## wherein R is hydrogen, lower alkyl of 1 to 7 carbons, or aryl, m is (10 to 40)% by weight and n is (100-m)% by weight.
Claim 5
Dependent Claim
16 words
In the method of claim 1, the improvement wherein said biologically active substance is an enzyme.
Claim 6
Dependent Claim
16 words
In the method of claim 1, the improvement wherein said biologically active substance is a hormone.
Claim 7
Dependent Claim
17 words
In the method of claim 1, the improvement wherein said biologically active substance is an enzyme inhibitor.
Claim 8
Dependent Claim
16 words
In the method of claim 1, the improvement wherein said biologically active substance is an antigen.
Claim 9
Dependent Claim
16 words
In the method of claim 1, the improvement wherein said biologically active substance is a drug.
Claim 10
Dependent Claim
40 words
The method of claim 1, the improvement wherein said body is in the shape of a hemisphere having a depression on its flat surface through which said active substance is released, said body being sealed everywhere except at said depression.
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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) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |