US5221698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bioactive composition
Assignee: University of Michigan (System)
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Filing: 1991-06-27
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Granted: 1993-06-22
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Expires: 2011-06-27
Abstract
Abstract An improved bioactive agent delivery composition and method of application are described. The composition comprises a bioactive agent, a hydrophilic polymer in an incompletely hydrated state and a substantially water-miscible solvent system. The agent and polymer are essentially dissolved in the solvent system to form a sprayable composition having a viscosity of less than 350 cP. Upon dilution with water, the viscosity of the composition increases to in excess of 1,000 cP to produce a retentive coating at the site of application which provides enhanced bioavailability of the agent.
Inventors
- 👤 Gordon L. Amidon
- 👤 Ramachandran Chandrasekharan
- 👤 Arthur H. Goldberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:24
CPC Classifications
A; A61; A61K; A61K47/00; A61K47/30; A61K47/32; A01; A01N; A01N25/00; A01N25/24; A61K47/36; A61K47/38; A61K9/00; A61K9/0012; A61K9/0019; A61K9/0043
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
78 words
A method of forming a bioactive coating on a substrate, the method comprising the steps of: applying a composition comprising a bioactive agent and hydrophilic polymer in an incompletely hydrated state essentially dissolved in a solvent system to said substrate, said composition having a viscosity of less than 350 centipoise; and diluting said composition with water, to hydrate said polymer and form a gel coating on the substrate, said coating having a viscosity in excess of 1,000 centipoise.
Claim 2
Independent Claim
78 words
A method of forming a bioactive coating on a substrate, the method comprising the steps of: applying a composition comprising a bioactive agent and hydrophilic polymer in an incompletely hydrated state essentially dissolved in a solvent system to said substrate, said composition having a viscosity of less than 350 centipoise; and diluting said composition with water, to hydrate said polymer and form a gel coating on the substrate, said coating having a viscosity in excess of 1,000 centipoise.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said step of applying comprises spraying said liquid composition onto the substrate.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the substrate is a moist region of the body of a living being.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein the solvent system comprises propylene glycol.
Claim 6
Dependent Claim
40 words
The method of claim 4 wherein the solvent system comprises a mixture of a first and a second solvent, said first solvent being propylene glycol in an amount of approximately between 30 and 55 percent by weight of said mixture.
Claim 7
Dependent Claim
25 words
The method of claim 5 wherein the second solvent is selected from the group consisting of dimethylacetamide, ethyl lactate, ethyl carbonate, dimethylformamide, dimethylsulfoxide, and dioxolanes.
Claim 8
Dependent Claim
12 words
The method of claim 1, wherein water is sprayed onto the substrate.
Claim 9
Dependent Claim
14 words
The method of claim 1, wherein the liquid composition and water are sprayed simultaneously.
Claim 10
Dependent Claim
11 words
The method of claim 7, wherein the substrate comprises plant foliage.
Claim 11
Dependent Claim
12 words
The method of claim 9, wherein the bioactive agent comprises a pesticide.
References Cited (Backward Citations)
US3920436A
Cited
EP0143297A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |