Patent US5013769A successfully refreshed from Google Patents.
US5013769A
Expired / Lapsed
US
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Method of making a hydrogel-forming wound dressing or skin coating material
Assignee: Medipro Sciences Ltd
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Filing: 1990-02-06
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Granted: 1991-05-07
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Expires: 2010-02-06
Abstract
Abstract The invention disclosed is a hydrogel-forming wound dressing or skin coating material suitable for household and veterinary use, consisting substantially entirely of wound-compatible and skin-compatible ingredients and comprising a first hydrophilic polymer, selected from polymers or copolymers of acrylic acid, polymers or copolymers of methacrylic acid, polymers or copolymers of itaconic acid, polymers or copolymers of maleic acid and polymers or copolymers of 3-butene-1,2,3-tricarboxylic acid, or combinations thereof, a second hydrophilic polymer which is capable of interacting with the first polymer to produce, upon drying, a hydrogel of improved water resistance and film forming properties relative to the first polymer alone and water. This material is film forming and substantially transparent but capable of being made opaque.
Inventors
- 👤 Douglas G. Murray
- 👤 Dennis C. Smith
- 👤 James E. Guillet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:12
CPC Classifications
A; A61; A61L; A61L26/00; A61L26/0061; A61L26/008; A61L26/0009; A61L26/0052; C; C09; C09D; C09D133/00; C09D133/02; C08; C08L; C08L39/00; C08L39/04; C08L39/06; C08L71/00; C08L71/02; C08L89/00; C08L89/04; C08L89/06
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
80 words
A method for making a hydrogel-forming wound dressing or skin coating material, said material comprising a first hydrophilic polymer selected from polymers of acrylic acid, a second hydrophilic polymer which is polyvinyl alcohol, and water, the method comprising: (a) preparing a homogenous solution of the first hydrophilic polymer with the second hydrophilic polymer at an elevated temperature; (b) diluting the solution produced in step (a) by mixing it with water and an organic solvent; and (c) de-aerating the resultant mixture.
Claim 2
Independent Claim
80 words
A method for making a hydrogel-forming wound dressing or skin coating material, said material comprising a first hydrophilic polymer selected from polymers of acrylic acid, a second hydrophilic polymer which is polyvinyl alcohol, and water, the method comprising: (a) preparing a homogenous solution of the first hydrophilic polymer with the second hydrophilic polymer at an elevated temperature; (b) diluting the solution produced in step (a) by mixing it with water and an organic solvent; and (c) de-aerating the resultant mixture.
Claim 3
Dependent Claim
20 words
The method according to claim 1 wherein the first hydrophilic polymer is polyacrylic acid of low and intermediate molecular weight.
Claim 4
Dependent Claim
21 words
The method according to claim 1 wherein the second hydrophilic polymer is a mixture of partially and fully hydrolyzed polyvinyl alcohol.
Claim 5
Dependent Claim
21 words
The method according to claim 1 including the additional step (d) of adding to the solution of step (a), compatible preservatives.
Claim 6
Dependent Claim
23 words
The method according to claim 4 wherein said preservatives are selected from the group consisting of sodium benzoate, sorbic acid and mixtures thereof.
Claim 7
Dependent Claim
24 words
The method of claim 1 including the additional step (e) of adding at least one suitable plasticizer to the solution resulting from step (a).
Claim 8
Dependent Claim
23 words
The method according to claim 6 wherein the plasticizer is selected from the group comprising glycerol, propylene glycol, sorbitol, gluconolactone and gluconic acid.
Claim 9
Dependent Claim
25 words
The method according to claim 6 including the additional step (f) of adding to the preservative containing mixture resulting from step (d), a biocompatible powder.
Claim 10
Dependent Claim
22 words
The method according to claim 8 wherein said powder is selected from the group comprising chitin, talc, cross-linked starch and cross-linked gelatin.
Claim 11
Dependent Claim
25 words
The method according to claim 8 including the subsequent step (g) of adding to the resultant mixture, a compatible soluble aluminum salt or derivative thereof.
Claim 12
Dependent Claim
25 words
The method according to claim 10 wherein said aluminum salt is selected from the group comprising ammonium alum, sodium, alum, potassium alum, and aluminum sulfate.
Claim 13
Dependent Claim
13 words
The method according to claim 11 wherein said aluminum salt is ammonium alum.
Claim 14
Independent Claim
130 words
A method for making a hydrogel-forming wound dressing or skin coating material, said material comprising a first hydrophilic polymer selected from polymers of acrylic acid and polymers of methacrylic acid or combinations thereof, a second hydrophilic polymer which is capable of interacting with the first hydrophilic polymer to produce, upon drying, a hydrogel of improved water-resistance and film-forming properties relative to the first polymer alone, and water, the method comprising: (a) mixing an aqueous solution of the first hydrophilic polymer with an aqueous solution of the second hydrophilic polymer to produce an aqueous phase and a gum or water-immiscible viscous liquid; (b) removing the aqueous phase; (c) processing the viscous liquid or gum to remove occluded water; and (d) mixing the gum or viscous liquid with a suitable organic solvent.
Claim 15
Independent Claim
130 words
A method for making a hydrogel-forming wound dressing or skin coating material, said material comprising a first hydrophilic polymer selected from polymers of acrylic acid and polymers of methacrylic acid or combinations thereof, a second hydrophilic polymer which is capable of interacting with the first hydrophilic polymer to produce, upon drying, a hydrogel of improved water-resistance and film-forming properties relative to the first polymer alone, and water, the method comprising: (a) mixing an aqueous solution of the first hydrophilic polymer with an aqueous solution of the second hydrophilic polymer to produce an aqueous phase and a gum or water-immiscible viscous liquid; (b) removing the aqueous phase; (c) processing the viscous liquid or gum to remove occluded water; and (d) mixing the gum or viscous liquid with a suitable organic solvent.
Claim 16
Dependent Claim
14 words
The method according to claim 13 wherein the first hydrophilic polymer is polyacrylic acid.
Claim 17
Dependent Claim
27 words
The method according to claim 13 wherein the second hydrophilic polymer is selected from gelating, polyvinyl pyrrolidone, polyethylene oxide and copolymers of ethylene oxide and propylene oxide.
Claim 18
Dependent Claim
19 words
The method according to claim 13 including the subsequent step (e) of heating the mixture resulting from step (d).
Claim 19
Dependent Claim
21 words
The method according to claim 13 including the subsequent step (f) of adding calcium chloride to the mixture from step (e).
Claim 20
Dependent Claim
17 words
The method according to claim 13 wherein the organic solvent is selected from isopropanol, ethanol and methanol.
Claim 21
Dependent Claim
26 words
The method according to claim 13 wherein the gum or viscous liquid of step (d) is mixed with at least one of glycerol and propylene glycol.
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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) | 1994-05-06 | 1994-11-05 | 1995-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-06 | 1998-11-05 | 1999-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-06 | 2002-11-05 | 2003-05-07 | $7700.00 | Window Closed / Lapsed |