WOUND DRESSING

Abstract

The present invention relates to a wound dressing composition for use as or in a wound dressing and to methods of making the wound dressing composition. The wound dressing composition comprises wicking material, and superabsorbent material that is punched into the wicking material. The action of punching the superabsorbent material into the wicking material acts to significantly increase the rate of absorption of the combination materials.

Claims

1-12. (canceled)

13. A wound dressing composition comprising a first layer of a wicking material and a second layer of an absorbent fibre material, whereby the absorbent material is punched into and/or through the wicking material.

14. A wound dressing composition according to claim 13, wherein at least a part of the absorbent material is exposed on a wound facing surface of the wicking layer.

15. A composition according to claim 13, wherein the absorbent material comprises a polymeric material.

16. A composition according to claim 13, wherein the polymeric material is selected from PVA, PEO and polyacrylic acid.

17. A composition according to claim 13, wherein the fibres form a non-woven layer.

18. A composition according to claim 13, wherein the wicking material comprises either a hydrophilic or hydrophobic material.

19. A composition according to claim 18, wherein the hydrophilic material is selected from polyurethane foams, and the hydrophobic material is selected from polyethylene foams.

20. A method of manufacturing a wound dressing composition, comprising the steps of: (a) providing a layer of a wicking material and a layer of an absorbent material; (b) attaching the layer of wicking material to the layer of absorbent material to form bonded layers; and (c) punching a plurality of holes in the bonded layers.

21. A method according to claim 20, wherein the layers are bonded using a heat meltable adhesive.

22. A method according to claim 20, wherein the plurality of holes is punched in the bonded layers using a roller having a plurality of needles thereon.

23. A use of a wound dressing composition according to claim 13 in absorbing fluid discharged from a physiological target, or in stemming a flow of a fluid discharged from a physiological target site.

24. A use of a wound dressing according to claim 20, in absorbing fluid discharged from a physiological target, or in stemming a flow of a fluid discharged from a physiological target site.

Description

[0087] Embodiments of the present invention will now be further described with reference to the following non-limiting examples and accompanying figures in which:

[0088] FIG. 1: is a cross-sectional representation of a wound dressing composition according to an embodiment of the present invention;

[0089] FIG. 2: is a cross-sectional representation of an alternative wound dressing composition of the present invention;

[0090] FIG. 3: is a cross-sectional representation of a wound dressing composition of the present invention comprising a skin protection layer;

[0091] FIG. 4: is a cross-sectional representation of a further alternative wound dressing composition of the present invention comprising a skin protection layer;

[0092] FIG. 5: is a cross-sectional representation of a further alternative wound dressing composition of the present invention comprising a skin protection layer;

[0093] FIG. 6: is a cross-sectional representation of a further alternative wound dressing composition of the present invention;

[0094] FIG. 7: is a cross-sectional representation of the wound dressing composition of FIG. 6 further comprising a skin protection layer;

[0095] Referring to FIGS. 1 and 2, there is shown a wound dressing composition (1) comprising a layer of wicking material (2), a layer of meltable adhesive (3), a layer of absorbent material (4), layer of anchor material (5) a layer of adhesive material (6), and a backing layer (7). The layer of absorbent material (4) is punched into the layer of wicking material (2). The layer of wicking material (2) can act as a wound contact layer. FIG. 2 also has two layers around the border comprising of a carrier layer (8) and a skin friendly adhesive layer (9).

[0096] The layer of wicking material (2) is adjacent to the wound site and will come into direct contact with the wound upon application of the wound dressing composition (1) to a wound. The layer of wicking material (2) is attached to the wound facing surface of the absorbent material (4) by any of the means described herein. Preferably, the layer of wicking material (2) is attached to the layer of absorbent material (4) using a powder adhesive. The layer of wicking material (2) also serves to prevent or reduce the leaching of fluids from the layer of absorbent material (4).

[0097] The meltable adhesive (3) is positioned between the layer of wicking material (2) and the absorbent material layer (4). In FIGS. 1 and 2, the bond created between these layers is such that it will not break when the respective materials get wet with wound fluid during use.

[0098] The anchor material (5) is attached to the non-wound facing surface of the absorbent material (4). Typically, the anchor material (5) is heat-bonded to the absorbent material (4). As described herein, the bond created between the anchor material (5) and the absorbent material (4) is such that it will not break when the respective materials get wet with wound fluid during use.

[0099] The adhesive layer (6) has a backing layer (7) attached to its non-wound facing surface. As with the anchor material (5), the backing layer (7) can be attached to the anchor material (5) by contacting the two materials together and applying pressure.

[0100] As can be seen in both FIGS. 1 and 2, the adhesive layer (6) and the backing layer (7) have a greater cross-sectional area than the anchor material (5), the absorbent material (4) and the layer of wicking material (2), creating a border portion (8). The wound facing surface of the backing layer (7) in the border portion (8) is, in use, applied directly to the patient's skin surrounding the wound site with the use of an adhesive (10). Thus, the adhesive layer (10) has the dual purpose of adhering to the anchor layer (5) and the skin of the patient.

[0101] FIG. 3 is an alternative design, whereby a perforated layer, comprising of a carrier layer, a layer of a pressure sensitive adhesive proximal to the absorbent layer (4) and a silicone adhesive layer proximal to the wound is used to envelope the fluid absorbing portion of the dressing. In doing so there is no requirement for the anchor layer.

[0102] FIGS. 4 and 5 are alternatives to FIGS. 1 and 2 whereby the adhesive portion of the dressing that is used to secure to the persons skin/wound overlaps the wound contact layer, but not fully across this layer, This layer can be perforated or non-perforated.

[0103] FIGS. 6 and 7 show a non-bordered version with and without an adhesive face.

[0104] In use, the wound dressing composition of the present invention is applied to a wound by contacting the wicking layer and/or the silicone layer with the wound site. The wound dressing composition can be affixed to the patient's skin by applying downward pressure to the border portion or the non-bordered part where no border is present, or by means of a secondary securement device. Wound exudates from the wound will be absorbed through the wicking layer and into the superabsorbent layers. This has the effect of drawing fluid away from the wound bed, creating a moisture level at the wound bed that is more conducive to healing.

EXAMPLES

[0105] The wound dressing compositions of the present invention do not delaminate, maintain a level of moisture and have a fast wicking rate under 60 seconds, preferably under 30 seconds for 1 ml of fluid. To test this, the following experiment was followed.

[0106] Test Methodology

[0107] Two island wound dressing in conjunction with the present invention as shown in FIG. 3 were prepared. The first wound dressing (T1) was made up of a superabsorbent layer of polyacrylate fibres gsm 200, an a pattern coated adhesive layer of a pressure-sensitive acrylic adhesive 20 gsm, a backing layer of a highly breathable polyurethane film, 30 micron thickness and an wicking layer of a polyurethane foam, 1.5 mm thickness and a superabsorbent polymer/dry hot meltable adhesive layer at 0.49 g per 100 cm.sup.2. The superabsorbent layer was bonded to the wicking layer and then punched into the wicking layer. The second wound dressing (T2) was made up of a superabsorbent layer of polyacrylate fibres gsm 250, an a pattern coated adhesive layer of a pressure-sensitive acrylic adhesive 20 gsm, a backing layer of a highly breathable polyurethane film, 30 micron thickness and an wicking layer of a polyurethane foam, 1.5 mm thickness and a dry hot meltable adhesive layer at 0.25 g per 100 cm.sup.2. The superabsorbent layer was bonded to the wicking layer and then punched into the wicking layer.

[0108] Two control dressings (C1 and C2) were constructed as described above, whereby the superabsorbent layers were not punched into the wicking layer.

[0109] All test dressings and control were packaged and sterilised using ethylene oxide sterilisation.

[0110] In the tests, Solution A is 142 mmol sodium ions and 2.5 mmol calcium ions as the chloride salt, Solution B is saline and Solution C is simulated wound fluid (50% peptone water and 50% fetal bovine serum).

[0111] To each test article and control, 1 ml of each of the solutions A, B and C were pipetted onto the adhesive wound contact surface of the dressings, turned such that the adhesive wound contact surface was uppermost from the bench. This forms a droplet of solution on the surface of the dressing. The time taken for the solution to be absorbed into the dressing was recorded.

TABLE-US-00001 Average time taken for 1 ml solution to be absorbed into the test article (seconds) Test article Solution A Solution B Solution C T1 10 9 16 T2 12 10 20 C1 70 75 90 C2 74 80 86

[0112] The above result show that the punching of the superabsorbent layer into the wicking layer significantly decreases the time taken for the fluid to be absorbed into the wound dressing.

[0113] It is of course to be understood that the present invention is not intended to be restricted to the foregoing examples which are described by way of example only.