Patent US4948575A successfully refreshed from Google Patents.
US4948575A
Expired / Lapsed
US
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Alginate hydrogel foam wound dressing
Assignee: 3M Co
•
Filing: 1989-01-24
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Granted: 1990-08-14
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Expires: 2009-01-24
Abstract
Abstract A dimensionally stable alginate hydrogel foam wound dressing that absorbs wound exudate without any appreciable swelling. The wound dressing is formed-in-place in the wound cavity or on the wound surface from a reactive composition that foams as it gels. The water-insoluble alginate hydrogel foam based wound dressing is made by mixing together the ingredients of a two component system; applying the resulting composite liquid mixture to a wound site; and allowing the composite mixture to react. One component contains an aqueous suspension of certain di-or trivalent metal salts and an effervescent compound. The second component contains an aqueous solution of a biocompatible, water-soluble acid. At least one compound, and preferably both, contain a water soluble alginate.
Inventors
- 👤 Susan M. Cole
- 👤 James E. Garbe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:04
CPC Classifications
A; A61; A61L; A61L26/00; A61L26/0061; A61L26/008; A61L26/0009; A61L26/0023; Y; Y10; Y10S; Y10S424/00; Y10S424/13
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
140 words
A method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing comprising the steps of: (I) mixing together, to form a composite liquid mixture, a first liquid component comprising: (a) an aqueous suspension of particles of a water-insoluble di- or trivalent metal salt that will react with an acid to form a water-soluble metal salt, and which has a di- or trivalent metal ion capable of complexing with pendant carboxylate groups on water-soluble alginates to form water-insoluble alginate hydrogels, and (b) an effervescent compound which effervesces upon reaction with an acid; and a second liquid component comprising an aqueous solution of a biocompatible, water-soluble acid, wherein at least one of said components further comprise water-soluble alginate dissolved therein; (II) applying said composite liquid mixture directly to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 2
Independent Claim
140 words
A method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing comprising the steps of: (I) mixing together, to form a composite liquid mixture, a first liquid component comprising: (a) an aqueous suspension of particles of a water-insoluble di- or trivalent metal salt that will react with an acid to form a water-soluble metal salt, and which has a di- or trivalent metal ion capable of complexing with pendant carboxylate groups on water-soluble alginates to form water-insoluble alginate hydrogels, and (b) an effervescent compound which effervesces upon reaction with an acid; and a second liquid component comprising an aqueous solution of a biocompatible, water-soluble acid, wherein at least one of said components further comprise water-soluble alginate dissolved therein; (II) applying said composite liquid mixture directly to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 3
Independent Claim
127 words
A method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing comprising the steps of: (I) mixing together a first liquid component comprising: (a) water, (b) water-soluble alginate, (c) water-insoluble di- or trivalent metal salt that will react with an acid to form a water-soluble metal salt, and which has a di- or trivalent metal ion capable of complexing with pendant carboxylate groups on said water-soluble alginate to form a water-insoluble alginate hydrogel, and (d) an effervescent compound which effervesces upon reaction with an acid; and a second liquid component comprising an aqueous solution of a biocompatible, water-soluble acid, to form a composite liquid mixture; (II) applying said composite liquid mixture directly to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 4
Independent Claim
127 words
A method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing comprising the steps of: (I) mixing together a first liquid component comprising: (a) water, (b) water-soluble alginate, (c) water-insoluble di- or trivalent metal salt that will react with an acid to form a water-soluble metal salt, and which has a di- or trivalent metal ion capable of complexing with pendant carboxylate groups on said water-soluble alginate to form a water-insoluble alginate hydrogel, and (d) an effervescent compound which effervesces upon reaction with an acid; and a second liquid component comprising an aqueous solution of a biocompatible, water-soluble acid, to form a composite liquid mixture; (II) applying said composite liquid mixture directly to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 5
Dependent Claim
40 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 2 wherein said water-soluble alginate is selected from the group consisting of the ammonium, magnesium, potassium, sodium, and lithium salts of alginic acid.
Claim 6
Dependent Claim
34 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 2 wherein said water-soluble alginate is selected from the group consisting of sodium alginate and potassium alginate.
Claim 7
Dependent Claim
43 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 2 wherein said water-insoluble di- or trivalent metal salt is selected from the group consisting of calcium carbonate, calcium phosphate dibasic, barium carbonate and zinc carbonate.
Claim 8
Dependent Claim
27 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 2 wherein said water-insoluble divalent metal salt is calcium carbonate.
Claim 9
Dependent Claim
37 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 2 wherein said biocompatible, water-soluble acid is selected from the group consisting of acetic, lactic, malic, gluconic, and ascorbic acids.
Claim 10
Dependent Claim
26 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 2 wherein said second component further comprises water-soluble alginate.
Claim 11
Dependent Claim
34 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 8 wherein the water-soluble alginate in both said first and second components is of the same composition.
Claim 12
Dependent Claim
34 words
The method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing as recited in claim 9 wherein said water-soluble alginate is selected from the group consisting of sodium alginate and potassium alginate.
Claim 13
Dependent Claim
33 words
The method of making, in situ, a water-insoluble alginate, hydrogel foam wound dressing as recited in claim 2 wherein said effervescent compound is selected from the group consisting of the alkali metal carbonates.
Claim 14
Dependent Claim
25 words
The method of making, in situ, a water-insoluble alginate, hydrogel foam wound dressing as recited in claim 2 wherein said effervescent compound is sodium carbonate.
Claim 15
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 1.
Claim 16
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 2.
Claim 17
Dependent Claim
13 words
An alginate hydrogel foam, wound dressing prepared by the method of claim 3.
Claim 18
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 4.
Claim 19
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 5.
Claim 20
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 10.
Claim 21
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 7.
Claim 22
Dependent Claim
12 words
An hydrogel foam wound dressing prepared by the method of claim 8.
Claim 23
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 13.
Claim 24
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 10.
Claim 25
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 11.
Claim 26
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 12.
Claim 27
Independent Claim
78 words
A method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing comprising the steps of: (I) mixing together a first liquid component comprising: (a) water, (b) sodium alginate, (c) calcium carbonate, and (d) sodium carbonate; and a second liquid component comprising: (e) water, (f) acetic acid, and (g) sodium alginate, to form a composite liquid mixture; (II) applying said composite liquid mixture directly to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 28
Independent Claim
78 words
A method of making, in situ, a water-insoluble alginate hydrogel foam wound dressing comprising the steps of: (I) mixing together a first liquid component comprising: (a) water, (b) sodium alginate, (c) calcium carbonate, and (d) sodium carbonate; and a second liquid component comprising: (e) water, (f) acetic acid, and (g) sodium alginate, to form a composite liquid mixture; (II) applying said composite liquid mixture directly to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 29
Dependent Claim
13 words
An alginate hydrogel foam wound dressing prepared by the method of claim 25.
Claim 30
Dependent Claim
137 words
An alginate hydrogel foam wound dressing made by the process comprising the steps of: (I) mixing together, to form a composite liquid mixture, a first liquid component comprising: (a) an aqueous suspension of particles of a water-insoluble di- or trivalent metal salt that will react with an acid to form a water-soluble metal salt, and which has a di- or trivalent metal ion capable of complexing with pendant carboxylate groups on water-soluble alginates to form water-insoluble alginate hydrogels, and (b) an effervescent compound with effervesces upon reaction with an acid; and a second liquid component comprising an aqueous solution of a biocompatible, water-soluble acid, wherein at least one of said components further comprise water-soluble alginate dissolved therein; (II) applying said composite liquid mixture directed to a wound site; and (III) allowing said composite liquid mixture to react.
Claim 31
Dependent Claim
137 words
An alginate hydrogel foam wound dressing made by the process comprising the steps of: (I) mixing together, to form a composite liquid mixture, a first liquid component comprising: (a) an aqueous suspension of particles of a water-insoluble di- or trivalent metal salt that will react with an acid to form a water-soluble metal salt, and which has a di- or trivalent metal ion capable of complexing with pendant carboxylate groups on water-soluble alginates to form water-insoluble alginate hydrogels, and (b) an effervescent compound with effervesces upon reaction with an acid; and a second liquid component comprising an aqueous solution of a biocompatible, water-soluble acid, wherein at least one of said components further comprise water-soluble alginate dissolved therein; (II) applying said composite liquid mixture directed to a wound site; and (III) allowing said composite liquid mixture to react.
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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) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |