Wound dressings

Abstract

A wound dressing comprises a wound-contacting layer composed of a mixture of honey and a moisture-absorbing agent; a water-permeable fabric backing layer; and an intermediate layer comprising water-permeable fabric impregnated with a mixture of honey and a moisture-absorbing agent.

1 . A wound dressing having honey and a moisture-absorbing agent, comprising a wound-contacting layer including a mixture of honey and a moisture-absorbing agent; a water-permeable fabric backing layer; and an intermediate layer comprising water-permeable fabric impregnated with a mixture of honey and a moisture-absorbing agent.  
     
     
         2 . A wound dressing according to  claim 1 , wherein said dressing is substantially impervious to liquid water but substantially permeable to water vapour.  
     
     
         3 . A wound dressing according to  claim 2 , wherein said dressing remains substantially impervious to liquid water but substantially permeable to water vapour even after gamma-irradiation.  
     
     
         4 - 18 . (canceled).  
     
     
         19 . A method of manufacturing a wound dressing, comprising the steps of: providing a layer of a water-permeable fabric material; providing a mixture of honey and a moisture-absorbing agent; spreading said mixture over said fabric layer; allowing a portion of said mixture to impregnate an upper sub-layer of said fabric layer; and allowing said mixture to set, thereby to produce a dressing comprising a wound-contacting layer including a mixture of honey and a moisture-absorbing agent, a water-permeable fabric backing layer, and an intermediate layer comprising fabric impregnated with said mixture of honey and moisture-absorbing agent.  
     
     
         20 . A method according to  claim 19 , wherein said mixture of honey and moisture-absorbing agent is allowed to impregnate said fabric layer to a depth of 100 μm to 1,000 μm.  
     
     
         21 - 23 . (canceled).  
     
     
         24 . A method according to  claim 19 , further comprising the step of attaching to said fabric layer an adhesive layer extending laterally outwardly beyond a periphery of said wound-contacting layer and being provided with adhesive material on such outward extension of its surface oriented towards said wound-contacting layer to provide adhesion of said adhesive layer to an area of skin of a patient to whom the dressing is applied, surrounding a wound to be treated.  
     
     
         25 . A method according to  claim 24 , wherein said adhesive layer does not overlie at least a substantial portion of said fabric layer.  
     
     
         26 . A method according to  claim 19 , further comprising the step of subjecting the dressing to gamma-irradiation.  
     
     
         27 . A method according to  claim 19 , wherein the mixture of honey and the moisture-absorbing agent is provided by continuous mixing in a twin-screw extruder.  
     
     
         28 . A method according  claim 27 , wherein said mixing is carried out in a twin-screw extruder having a series of temperature zones down a length of said extruder.  
     
     
         29 . A method according to  claim 27 , wherein the mixture of honey and the moisture-absorbing agent is provided at a temperature such that gelling starts to occur immediately on extrusion through said twin-screw extruder.  
     
     
         30 . A method according to  claim 27 , wherein the mixture of honey and the moisture-absorbing agent is provided at a temperature of about 75° C. to about 80° C.  
     
     
         31 . A method according to  claim 27 , wherein the mixture of honey and the moisture-absorbing agent is laid onto a support paper.  
     
     
         32 . A method according to  claim 31 , wherein the mixture of honey and the moisture-absorbing agent laid onto the support paper is passed in direct contact with the layer of the water-permeable fabric material through calendar rolls, to thereby achieve partial impregnation of the fabric material with the mixture.  
     
     
         33 . A method according to  claim 32 , wherein the layer of the water-permeable fabric material is passed through calendar rolls together with a backing release paper.  
     
     
         34 . A wound dressing according to  claim 1 , wherein an identity of said moisture-absorbing agent and a ratio of honey with respect to said agent are chosen so that said wound-contacting layer forms a substantially homogeneous solid sheet.  
     
     
         35 . A wound dressing according to  claim 1 , wherein said wound-contacting layer and said intermediate layer form a first continuous phase, and wherein said fabric layer and said intermediate layer form a second continuous phase, said first and second continuous phases overlapping to form said intermediate layer.  
     
     
         36 . A wound dressing according to  claim 35 , wherein said intermediate layer has a thickness of between 100 μm and 1,000 μm.  
     
     
         37 . A wound dressing according to  claim 36 , wherein said intermediate layer has a thickness of between 200 μm and 500 μm.  
     
     
         38 . A wound dressing according to  claim 35 , wherein said wound-contacting layer is free from fabric and said fabric layer is free from honey.  
     
     
         39 . A wound dressing according to  claim 1 , wherein a weight ratio of moisture-absorbing agent to honey in said wound-contacting and intermediate layers is between 1:2 and 1:14.  
     
     
         40 . A wound dressing according to  claim 39 , wherein said ratio is in the range 1:4 to 1:10.  
     
     
         41 . A wound dressing according to  claim 40 , wherein said ratio is in the range 1:4 to 1:5.  
     
     
         42 . A wound dressing according to  claim 1 , wherein said moisture-absorbing agent is an alginate or carboxymethyl cellulose powder.  
     
     
         43 . A wound dressing according to  claim 42 , wherein said moisture-absorbing agent is sodium alginate.  
     
     
         44 . A wound dressing according to  claim 1 , wherein said dressing has a 24-hour moisture vapour transmission rate of at least 20 g per 100 cm 2  and a 24-hour total fluid handling capacity of at least 35 g per 100 cm 2 .  
     
     
         45 . A wound dressing according to  claim 1 , further comprising an adhesive layer attached to or integral with said fabric backing layer, said adhesive layer extending laterally outwardly beyond a periphery of said wound-contacting layer and being provided with adhesive material on such outward extension of its surface oriented towards said wound contacting layer to provide adhesion of said adhesive layer to an area of skin of a patient to whom the dressing is applied, surrounding a wound to be treated.  
     
     
         46 . A wound dressing according to  claim 45 , wherein at least a substantial portion of the fabric backing layer is not overlain by said adhesive layer.  
     
     
         47 . A wound dressing according to  claim 1 , wherein the dressing has been gamma-irradiated.  
     
     
         48 . A wound dressing according to  claim 47 , wherein the dressing is gamma-irradiated by at least 25 kGy.