WOUND DRESSING COMPRISING AN ANTIMICROBIAL COMPOSITION
Methods, processes and compositions are provided for improved wound dressings comprising an antimicrobial composition. The wound dressings maintain conformability and strength, as well as antimicrobial performance, upon use after storage.
1 . A packaged wound dressing comprising modified cellulosic fibres treated with an antimicrobial composition comprising a source of an antimicrobial metal ion and a quaternary cationic surfactant, the dressing having a moisture content of between 10% and 20% by weight.
2 . A wound dressing as claimed in claim 1 wherein the package maintains the moisture content of the dressing in the range of 10% and 20% until the point of use.
3 . A wound dressing as claimed in claim 1 or claim 2 wherein the antimicrobial metal ion is selected from the group of the transition metals but particularly silver, iron, nickel, copper, chromium, manganese, gold, gallium, mercury, lead, aluminium, lead, zinc, bismuth, tin and palladium or combinations thereof.
4 . A wound dressing as claimed in any preceding claim wherein the metal ion is silver.
5 . A wound dressing as claimed in any preceding claim wherein the metal ion is included in the dressing at a level of from 0.01% to 10% by weight, more preferably 0.1% to 5% and even more preferably 0.5% to 1.5% by weight.
6 . A wound dressing as claimed in any preceding claim wherein the quaternary cationic surfactant is a quaternary ammonium surfactant.
7 . A wound dressing as claimed in any preceding claim wherein the cationic surfactant is selected from the group of the salts where the cation is benzethonium, benzalkonium, dimethyldiakylonium, alkylpyridinium and alkyltrimethylammonium.
8 . A wound dressing as claimed in any preceding claim wherein the dressing further comprises a chelating agent for example, EDTA present as the di-, tri- or tetra-basic salts of EDTA.
9 . A wound dressing as claimed in claim 8 wherein the metal chelating agent is present in the dressing at a level of 0.1% to 4% by weight, more preferably less than 2% by weight, more preferably 0.2 to 1% by weight.
10 . A wound dressing as claimed in any of the preceding claims wherein the moisture content is between 11% and 18% by weight.
11 . A wound dressing as claimed in any of the preceding claims wherein the moisture content is between 11.5% and 15% by weight.
12 . A wound dressing as claimed in any of the preceding claims wherein the moisture content is between 11.5% and 13% by weight.
13 . A process for preparing the wound dressing as claimed in any of the preceding claims.
14 . A method for maintaining conformabilty of a wound dressing comprising providing a wound dressing as claimed in any of claims 1 to 12 .