Wound dressing

• US 4,664,662 A
• Filed: 07/31/1985
• Issued: 05/12/1987
• Est. Priority Date: 08/02/1984
• Status: Expired due to Term

• Current Assignee: Smith and Nephew PLC 2 Temple Place Victoria Embankment London WC2R 3BP United Kingdom
• Original Assignee: Smith and Nephew Associated Companies PLC
• Inventors: Webster, David F.
• Primary Examiner(s): Yasko, John D.
• Application Number:
  US06/760,827
• Time in Patent Office: 650 Days
• Field of Search: 604/369, 604/368, 604/367, 604/904, 604/370, 604/358, 128/155, 128/156
• US Class Current: 602/47
• CPC Class Codes: A61F 13/00063 comprising medicaments or additives, e.g. odor control, PH control, debriding, antimicrobic drug delivery dressings A61K9/70; chemical aspect of the additives A61L15/00
• CPC Class Codes: A61F 13/01021 characterised by the structure of the dressing
• CPC Class Codes: A61F 13/069 Decubitus ulcer bandages
• CPC Class Codes: A61F 13/537 characterised by a layer facilitating or inhibiting flow in one direction or plane, e.g. a wicking layer A61F13/538 takes precedence
• CPC Class Codes: A61F 2013/00119 elastic
• CPC Class Codes: A61F 2013/00157 for burns or skin transplants A61F2013/00187 takes precedence; not adhering to the wound A61F2013/00217
• CPC Class Codes: A61F 2013/00217 not adhering to the wound with wax A61F2013/00161
• CPC Class Codes: A61F 2013/00251 with macroscopic openings
• CPC Class Codes: A61F 2013/00519 for treating burn bandages for burns or skin transplants A61F2013/00157
• CPC Class Codes: A61F 2013/0054 for deep wounds
• CPC Class Codes: A61F 2013/0074 containing foams
• CPC Class Codes: A61F 2013/00859 with macroscopic openings
• CPC Class Codes: A61F 2013/00897 package for individual plaster
• CPC Class Codes: A61F 2013/00927 with biological activity, e.g. enzymes for debriding wounds or others, collagen or growth factors
• CPC Class Codes: A61F 2013/530802 characterized by the foam or sponge other than superabsorbent A61F2013/530649 takes precedence
• CPC Class Codes: A61F 2013/53782 with holes
• CPC Class Codes: A61L 15/225 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 15/26 Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof A61L15/225 takes precedence
• CPC Class Codes: A61L 15/425 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 25/04 Homopolymers or copolymers of styrene
• CPC Class Codes: C08L 31/04 : Homopolymers or copolymers of vinyl acetate
• CPC Class Codes: C08L 75/04 : Polyurethanes

Abstract

An absorbent, non-adherent wound dressing suitable for use in deep and cavernous wounds is described. The dressing comprises an absorbent material in the form of individual pieces of a conformable, resilient, absorbent hydrophilic foam retained within a porous bag formed from a perforated polymeric film. In a preferred form the foam is a hydrophilic polyurethane foam and the perforated polymeric film is a contoured net of a thermoplastic elastomeric polymer. A non-woven fabric may be additionally present between the perforated polymeric film and the pieces of foam. The dressings can absorb large volumes of wound exudate without adhering to the wound.

Claims

1. A sterile, absorbent, non-adherent wound dressing suitable for use on deep wounds which dressing comprises an absorbent material contained within a porous bag, said absorbent material comprising individual pieces of a conformable, resilient, absorbent hydrophilic foam and said bag being formed from a perforated polymeric film and in which there is additionally present between the perforated polymeric film and the pieces of foam a non-woven fabric comprising a mixture of rayon and polypropylene fibers with an uncompressed thickness of from 0.4 to 2 mm.

2. A wound dressing according to claim 1 in which the hydrophilic foam is an open cell foam in which the cell size is from 30 μ

m to 700 μ

m and from 20 to 70% of the total membrane area of the cells are membrane openings.

3. A wound dressing according to claim 1 in which the pieces of foam have dimensions of from 3×

3 to 7×

7 mm and have a thickness of from 2 to 10 mm.

4. A wound dressing according to claim 1 in which the hydrophilic foam is a hydrophilic polyurethane foam.

5. A wound dressing according to claim 1 in which the hydrophilic foam is a foam containing a non-ionic surfactant.

11. A wound dressing according to claim 1 or 6 in which the dressing additionally contains a therapeutically effective amount of a physiologically active agent.

12. A wound dressing according to claim 1 or 6 which is sterile and is packaged in a bacteria proof pack.

6. A sterile, absorbent, non-adherent wound dressing suitable for use on deep wounds which dressing comprises an absorbent material contained within a porous bag, said absorbent material comprising individual pieces of a comformable, resilient, absorbent hydrophilic foam and said bag being formed from a perforated polymeric film, in which the perforated film is in the form of a contoured net comprising a film of thermoplastic elastomer having depressions impressed out of the plane of the film each depression having an aperture at the bottom.

7. A wound dressing according to claim 6 in which the thermoplastic elastomer comprises a blend of 40 to 90 parts by weight ethylene-vinyl acetate copolymer and 60 to 10 parts by weight of polystyrene.

8. A wound dressing according to claim 6 in which the area of an aperture is equivalent to the area of a circle having a diameter of 0.5 to 3 mm.

9. A wound dressing according to claim 6 in which the contoured net has fibers adhered to the depressions impressed out of the plane of the film whereby the apertures are crossed by the fibers.

10. A wound dressing according to claim 9 in which the fibres are formed by spraying a solution of the polymer of the fibres in a volatile solvent allowing the solvent to evaporate and catching the fibres so formed in the embossed surface of the contoured net.

13. A wound dressing according to claim 6 in which the hydrophilic foam is an open cell foam in which the cell size is from 30 μ

m to 70 μ

m and from 20 to 70% of the total membrane area of the cells are membrane openings.

14. A wound dressing according to claim 6 in which the pieces of foam have dimensions of from 3×

3 mm to 7×

7 mm and have a thickness of from 20 to 10 mm.

15. A wound dressing according to claim 6 in which the hydrophilic foam is a hydrophilic polyurethane foam.

16. A wound dressing according to claim 6 in which the hydrophilic foam is a foam containing a non-ionic surfactant.

17. A method of treating a deep and exuding wound by applying to the wound a sterile absorbent, non-adherent wound dressing comprising an absorbent material contained within a water permeable porous bag, said absorbent material comprising individual pieces of conformable, resilient, absorbent hydrophilic foam and said bag being formed from a perforated polymeric film and in which there is additionally present between the perforated polymeric film and the pieces of foam a non-woven fabric comprising a mixture of rayon and polypropylene fibers with an uncompressed thickness of from 0.4 to 2 mm.

18. A method of treating a wound according to claim 17 in which the hydrophilic foam is an open cell foam in which the cell size is from 30 μ

m to 700 μ

m and from 20 to 70% of the total membrane area of the cells are membrane openings.

19. A method according to claim 17 in which the pieces of foam have dimensions of from 3×

3 to 7×

7 mm and have a thickness of from 2 to 10 mm.

20. A method according to claim 17 in which the hydrophilic foam is a hydrophilic polyurethane foam.

21. A method according to claim 17 in which the hydrophilic foam is a foam containing a non-ionic surfactant.

22. A method of treating a deep and exuding wound by applying to the wound a sterile absorbent, non-adherent wound dressing comprising an absorbent material contained within a water permeable porous bag, said absorbent material comprising individual pieces of a conformable, resilient, absorbent hydrophilic foam and said bag being formed from a perforated polymeric film, in which the perforated polymeric film is in the form of a contoured net comprising a film of thermoplastic elastomer having depressions impressed out of the plane of the film each depression having an aperture at the bottom.

23. A method according to claim 22 in which the thermoplastic elastomer comprises a blend of 40 to 90 parts by weight ethylene-vinyl acetate copolymer and 60 to 10 parts by weight of polystyrene.

24. A method according to claim 22 in which the area of an aperture is equivalent to the area of a circle having a diameter of 0.5 to 3 mm.

25. A method according to claim 22 in which the contoured net has fibers adhered to the depressions impressed out of the plane of the film whereby the apertures are crossed by the fibers.

26. A method according to claim 25 in which the fibers are formed by spraying a solution of the polymer of the fibers in a volatile solvent allowing the solvent to evaporate and catching the fibers so formed in the embossed surface of the contoured net.

27. A method according to claim 22 in which the dressing additionally contains a therapeutically effective amount of a physiologically active agent.