MULTI-LAYER WOUND CARE PRODUCT WITH PERFORATED RELEASE LAYER

Abstract

A multi-layered wound care product includes an upper liquid-absorbing layer, an intermediate occlusive layer; and an active agent-releasing bottom layer. The latter two layers have common pores or perforations that enable the passage of wound exudate through the two layers to reach the liquid-absorbing layer. A use of the multi-layered wound care product for treatment of acute and chronic wounds and a method of producing the multi-layered wound care product are also provided.

Claims

1. A multilayered wound care product comprising: an upper liquid-absorbing layer; an intermediate occlusive layer; and a bottom active agent-releasing layer; wherein the occlusive layer and the active agent-releasing layer are sheet-like layers with pores or perforations, wherein each pore or perforation is a common pore or perforation that extends through a whole thickness of both the intermediate occlusive layer and the active agent-releasing layer that enable a passage of wound exudate through the common pores or perforations of such two layers to reach the liquid-absorbing layer and simultaneously enable a release of an active agent from an area between the pores or perforations to enter a wound site.

2. The multilayered wound care product of claim 1, wherein the occlusive layer is impermeable for fluids and prevents the active agent from spreading to the upper liquid-absorbing layer.

3. The multilayered wound care product of claim 1, wherein the layers are connected by use of an adhesive or by welding, sealing or laminating using at least one of temperature and pressure.

4. The multilayered wound care product of claim 1, wherein the upper liquid-absorbing layer contains at least one absorbent material selected from a group consisting of polymer foams, sponges, hydrocolloids, hydrogels and hydrophilic polymers such as superabsorbing polymers.

5. The multilayered wound care product of claim 1, wherein the intermediate occlusive layer is a metal layer or a polymer layer of one of the following polymers: polyvinylidene chloride, polyethylene terephthalate (PET), oriented polypropylene (OPP), biaxially oriented polypropylene (BOPP), oriented polyamide (OPA), biaxially oriented polyamide (BOPA), or a multi-layer high barrier film, selected from a group consisting of polyethylene/ethyl vinyl alcohol copolymer/polyethylene (PE/EVOH/PE), PP/EVOH/PP, PP/EVOH/PE, polyamide/polyethylene (PA/PE), PE/PA/PE, PP/PA/PE, PA/EVOH/PA/PE and PP/PA/EVOH/PA/PE, EVOH/OPP, EVOH/BOPP, EVOH/OPA, EVOH/BOPA and PVDC/PET, or a metal-coated form of polymeric films.

6. The multilayered wound care product of claim 1, wherein the active agent-releasing layer comprises an active agent being a therapeutic gas selected from a group consisting of oxygen, ozone, carbon dioxide, nitric oxide or combinations thereof, wherein the wound care product further comprises a gas-permeable layer oriented towards a treatment site having common pores or perforations with the active agent-releasing layer and the occlusive layer.

7. The multilayered wound care product of claim 1, wherein the active agent-releasing layer comprises different reactants that are separated from each other by a barrier, whereby breaking or removing the barrier allows a mixing of the reactants in order to generate the active agent.

8. The multilayered wound care product of claim 7, wherein a first reactant is an NO donor and a second reactant is a reducing agent or a proton donor.

9. The multilayered wound care product of claim 8, wherein the NO donor is selected from a group consisting of inorganic nitrite salts, alkyl nitrites such as isopentyl nitrite, diazeniumdiolated organic compounds, trans[RuCl([15]aneN4)NO].sup.2+, Nitrosyl-ligands, 6-nitrobenzo[a]pyrol, S-nitroso-glutathione, 5-nitroso-thiols, S-nitroso-N-acetyl-D-penicillamine (SNAP), L-arginine, L-citrulline, nitroglycerin (GTN), isosorbide 5-mononitrate (ISMN), isosorbide dinitrate (ISDN), pentaerythritol tetranitrate (PETN), erythrityl tetranitrate (ETN), amino acid derivatives such as N-hydroxy-L-arginine (NOHA), N.sup.6-(Iiminoethyl)lysine) (L-NIL), L-N.sup.5-(1-iminoethyi)ornithine (LN-NIO), N.sup.a-methyl-L-arginine (L-NMMA), S-nitroso glutathione (SNOG), S,S-dinitrosodithiol (SSDD), 2-[(pyridin-3-ylcarbonyl)amino]ethyl nitrate (nicorandil), sodium nitroprusside (SNP), S-nitroso-N-acetylpenicillamine (SNAP), [8-[2-hydroxy-3-(propan-2-ylamino)propoxy]-3,4-dihydro-2H-chromen-3-yl] nitrate (Nipradilol), 3-morpholino-sydnonimine (SIN-1), molsidomine, DEA-NONOate (2-(N,N-diethylamino)diazenolate-2-oxide), spermine NONOate (N-[4-[1-(3-aminopropyl)-2-hydroxy-2-nitrosohydrazino]butyl-1,3-propanediamine), 3-(5-hydroxymethyl-2 furyl)-1-benzyl indazole (YC-1), nitroaniline derivatives, 2-methyl-2-nitrosopropane, imidazoyl derivatives, nitrate ester, hydroxyl nitrosamine, hydroxylamine and hydroxyl urea, and combinations thereof.

10. The multilayered wound care product of claim 9, wherein the inorganic nitrite salts are selected from a group consisting of LiNO.sub.2, NaNO.sub.2, KNO.sub.2, RbNO.sub.2, CsNO.sub.2, FrNO.sub.2, Be(NO.sub.2).sub.2, Mg(NO.sub.2).sub.2, Ca(NO.sub.2).sub.2, Sr(NO.sub.2).sub.2, Ba(NO.sub.2).sub.2, and Ra(NO.sub.2).sub.2 and combinations thereof.

11. The multilayered wound care product of claim 8, wherein the reducing agent is selected from a group consisting of ascorbic acid, cysteine, glutathione, penicillamine, N-acetylcysteine, iodine, hydroquinone, mercaptosuccinic acid, thiosalicylic acid, methylthiosalicylic acid, dithiothreitol, dithioerythritol, 2-mercaptoethanol, FeSO.sub.4, and FeCl.sub.2, and combinations thereof.

12. The multilayered wound care product of claim 11, wherein the reducing agent is capable of forming a transient nitrosyl complex and is selected from agroup consisting of Cu, Cu(I), V(III), Mo(VI), Fe(II), I.sup., Ti(III), Co(II), Mn(II), and Cr(III) and their salts.

13. The multilayered wound care product of claim 8, wherein the proton donor is selected from a group consisting of H.sub.2SO.sub.4, HCl, HBr, HI, HNO.sub.3, acetic acid, lactic acid, tartaric acid, ascorbic acid, citric acid, salicylic acid, and combinations thereof.

14. The multilayered wound care product of claim 1, wherein the active agent-releasing layer is coated on a wound-facing side with an pressure sensitive adhesive wound contact layer, a material of which is selected from one of the following materials polyacrylate adhesive, silicone, natural rubber-based adhesive, synthetic rubber-based adhesive or hotmelt, such as polyolefine, polyacrylate or rubber-based hotmelt.

15. The multilayered wound care product of claim 1, wherein the pores or perforations have a triangular, rectangular, hexangular, ellipsoid or circular form.

16. The multilayered wound care product of claim 1, wherein the pores or perforations account for between 1% to 50% of an area of at least one of the active agent-releasing layer and the occlusive layer.

17. The multilayered wound care product of claim 1, wherein the pores or perforations are evenly distributed on the area of the active agent releasing layer.

18. The multilayered wound care product of claim 1, wherein the occlusive layer exhibits a circumferential rim at the pores or perforation by projecting over an area of the active agent-releasing layer.

19. The multilayered wound care product of claim 1, wherein the upper liquid-absorbing layer, the intermediate occlusive layer, and the active agent-releasing bottom layer are bonded at a border portion or at edges of said layers.

20. A method of treatment of chronic wounds, comprising: providing the multilayered wound care product of claim 1; and applying the multilayered wound care product to treat one of the following: burns, partial and full-thickness wounds, pressure ulcers, venous ulcers, arterial ulcers, diabetic ulcers, chronic vascular ulcers, draining wounds, tunneled or undermined wounds, surgical wounds such as donor sites/grafts, post-Mohs surgery, post-laser surgery, podiatric dehiscence, and wound dehiscence, trauma wounds such as abrasions, lacerations, second-degree burns, and skin tears.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0213] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0214] The invention will now be described, by way of example, based on embodiments with reference to the accompanying drawings.

[0215] In the drawings:

[0216] FIG. 1 shows a principal sketch of the wound care product according to a first embodiment in cross section (A), in a perspective view (B) or in a top view (C).

[0217] FIG. 2 shows examples for perforation patterns for the wound care product.

[0218] FIG. 3 shows the influence of the chosen perforation pattern on the absorption capacity of the wound care article.

[0219] FIG. 4 shows a principal sketch of the wound care product according to a second embodiment in a perspective view.

[0220] FIG. 5 shows a principal sketch of the wound care product according to a third embodiment in cross section.

[0221] In the Figures, like numbers refer to like objects throughout. Objects in the Figures are not necessarily drawn to scale.

DETAILED DESCRIPTION OF EMBODIMENTS

[0222] Various embodiments of the invention will now be described by means of the Figures.

[0223] FIG. 1 shows a principal sketch of the wound care product according to a first embodiment in cross section (A), in a perspective view (B) or in a top view (C) consisting of three layers, namely the active-agent releasing layer 3, the intermediate occlusive layer 2 and the liquid-absorbing layer 1 as top layer. The wound care product is shown in a cross section/perspective view and may be applied as such to a skin wound. To this, the wound care product has a surface that will face the wound when being applied and will come in direct contact with the wound, and has an opposite surface that will face away from the wound and will thus initially not contact the wound when applied.

[0224] FIG. 2 shows examples for perforation patterns for the wound care product.

[0225] FIG. 3 shows the influence of the chosen perforation pattern on the absorption capacity of the wound care article

[0226] FIG. 4 shows a principal sketch of the wound care product according to a further embodiment in a perspective view consisting of five layers, namely from top to bottom the cover layer 5, the liquid-absorbing layer 1, the occlusive layer 2, the active-agent releasing layer 3, and the gas-permeable layer 6 formed as a membrane. Note that the three most proximal layers comprise common circular perforations, so that the wound exudate can pass freely through these three layers in order to reach the liquid absorbing layer.

[0227] FIG. 5 shows a principal sketch of the wound care product according to another embodiment for release of a gas as active agent in cross section consisting of four layers, namely the gas-permeable layer 6, the gas releasing layer 3, the intermediate occlusive layer 2 and the liquid-absorbing layer 1 as top layer. Notably, the gas-permeable layer and the occlusive layer are sealed in the periphery and around the pores to surround the gas releasing layer, forming a pouch from which the gas can only be released through the gas-permeable layer facing the wound site.

[0228] While the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive.

[0229] From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the art and which may be used instead of or in addition to features already described herein.

[0230] Variations to the disclosed embodiments can be understood and effected by those skilled in the art, from a study of the drawings, the disclosure and the appended claims. In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality of elements or steps. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0231] Any reference signs in the claims should not be construed as limiting the scope thereof.

LIST OF REFERENCE SIGNS

[0232] 1 liquid absorbing layer [0233] 2 occlusive layer [0234] 3 active-agent releasing layer [0235] 4 pores [0236] 5 cover layer [0237] 6 Gas-release membrane as gas-permeable layer