US4646730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color stabilized hydrogel dressing and process
Assignee: Ethicon Inc
•
Filing: 1986-05-23
•
Granted: 1987-03-03
•
Expires: 2006-05-23
Abstract
Abstract A polyvinylpyrrolidone(PVP)/Silver Sulfadiazine (SSD) hydrogel dressing in which the gel is formed by the use of electron beam (E-Beam) radiation to cross-link the polyvinylpyrrolidone (PVP); in which the color of the hydrogel dressing has been stabilized by the addition thereto of magnesium trisilicate and, optionally but preferably, also hydrogen peroxide and/or polyacrylic acid is disclosed; and also the process of stabilizing the color by adding magnesium trisilicate, to a water dispersion of PVP and SSD before it is exposed to E-Beam radiation is disclosed.
Inventors
- 👤 Edward Schonfeld
- 👤 James W. McGinity
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:53
CPC Classifications
A; A61; A61L; A61L26/00; A61L26/0061; A61L26/008; A61L26/0009; A61L26/0014; A61L26/0066; A61L2300/00; A61L2300/10; A61L2300/102; A61L2300/104; A61L2300/40; A61L2300/404
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
45 words
A color stabilized hydrogel dressing comprising a non-rigid layer of cross-linked polyvinylpyrrolidone gel having incorporated therein at least 0.1 percent by weight of silver sulfadiazine, which gel has been exposed to E-beam radiation, and which gel also contains a color stabilizing amount of magnesium trisilicate.
Claim 2
Dependent Claim
45 words
A color stabilized hydrogel dressing comprising a non-rigid layer of cross-linked polyvinylpyrrolidone gel having incorporated therein at least 0.1 percent by weight of silver sulfadiazine, which gel has been exposed to E-beam radiation, and which gel also contains a color stabilizing amount of magnesium trisilicate.
Claim 3
Dependent Claim
30 words
The color stabilized hydrogel dressing of claim 1 wherein the magnesium trisilicate is present in an amount between 0.5 and 5.0 percent, based on the total weight of the gel.
Claim 4
Dependent Claim
22 words
The color stabilized hydrogel dressing of claim 2 wherein the magnesium trisilicate is present in an amount between 0.5 and 2.0 percent.
Claim 5
Dependent Claim
12 words
The color stabilized hydrogel dressing of claim 1 which also contains glycerine.
Claim 6
Dependent Claim
30 words
The hydrogel dressing of claims 1 or 4 which also contains between 0.05 and 0.7 percent of polyacrylic acid or polymethacrylic acid, based on the total weight of the gel.
Claim 7
Dependent Claim
23 words
The stabilized hydrogel dressing of claims 1, 4 or 5, which also contains from 0.25 to one percent by weight of hydrogen peroxide.
Claim 8
Dependent Claim
44 words
The process of stabilizing the color of the polyvinylpyrrolidone silver sulfadiazine gel dressing which results from the E-Beam radiation of a water dispersion of polyvinylpyrrolidone and silver sulfadiazine which comprises adding magnesium trisilicate to the water dispersion before it is exposed to E-beam radiation.
Claim 9
Dependent Claim
44 words
The process of stabilizing the color of the polyvinylpyrrolidone silver sulfadiazine gel dressing which results from the E-Beam radiation of a water dispersion of polyvinylpyrrolidone and silver sulfadiazine which comprises adding magnesium trisilicate to the water dispersion before it is exposed to E-beam radiation.
Claim 10
Dependent Claim
32 words
The process of claim 7 wherein polyacrylic acid or polymethacrylic acid or acrylic acid monomer is added to the polyvinylpyrrolidone/silver sulfadiazine/magnesium trisilicate water dispersion before said dispersion is exposed to E-Beam radiation.
Claim 11
Dependent Claim
26 words
The process of claim 8 wherein hydrogen peroxide is added to the polyvinylpyrrolidone/silver sulfadiazine/magnesium trisilicate containing water dispersion before said dispersion is exposed to E-Beam radiation.
Claim 12
Dependent Claim
29 words
The process of claim 7, 8 or 9 in which glycerine is also added to the polyvinylpyrrolidone silver sulfadiazine/magnesium trisilicate containing water dispersion prior to exposure to E-Beam radiation.
References Cited (Backward Citations)
US4192727A
Cited
US4411754A
Cited
US4209605A
Cited
US4377010A
Cited
US4362841A
Cited
US4263185A
Cited
US4552138A
Cited
US4548847A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |