Composition comprising antimicrobial metal ions and a quaternary cationic surfactant

Abstract

The present invention relates to an antimicrobial composition suitable for use on skin and wounds comprising a source of an antimicrobial metal ion and a quaternary cationic surfactant.

1 . An antimicrobial composition for treating wound bacteria in a biofilm, the composition comprising ionic silver, EDTA at a level of from 0.01% to 10% by weight, and a quaternary cationic surfactant, wherein the quaternary cationic surfactant is present at a level of more than or equal to 0.025% by weight, wherein the composition has a pH from 4 to 8, wherein the ionic silver, the EDTA, and the quaternary cationic surfactant are present in the composition in amounts that provide synergistic antimicrobial activity against the wound bacteria, and wherein the composition is in the form of a thin soluble film, the thin soluble film being suitable for lamination to a wound dressing. 
     
     
         2 . A composition as claimed in  claim 1 , wherein the ionic silver is present at a level of from 0.00001% to 1.0% by weight of the composition. 
     
     
         3 . A composition as claimed  claim 1 , wherein the cationic surfactant is selected from a group of the salts where the cation is benzethonium, benzalkonium, dimethyldiakylonium, alkylpyridinium and alkyltrimethylammonium. 
     
     
         4 . A composition as claimed in  claim 1 , wherein the quaternary cationic surfactant is present at a level of from 0.05% to 4% by weight. 
     
     
         5 . A composition as claimed in  claim 1 , wherein the EDTA is present as a di-, tri- or tetra-basic salt of EDTA. 
     
     
         6 . A composition as claimed in  claim 1 , wherein the EDTA is present in the composition at a level of 0.1% to 4% by weight of the composition. 
     
     
         7 . A process for making an antimicrobial wound dressing comprising:
 (i) obtaining an absorbent wound dressing, and   (ii) treating the wound dressing with an antimicrobial composition in the form of a thin soluble film, the thin soluble film being laminated to the wound dressing and for treating wound bacteria in a biofilm, wherein the composition comprises ionic silver, EDTA at a level of from 0.01% to 10% by weight, and a quaternary cationic surfactant, wherein the quaternary cationic surfactant is present at a level of more than or equal to 0.025% by weight, wherein the composition has a pH from 4 to 8, and wherein the ionic silver, the EDTA, and the quaternary cationic surfactant are present in the composition in amounts that provide synergistic antimicrobial activity against the wound bacteria.   
     
     
         8 . A composition as claimed in  claim 1 , wherein the quaternary cationic surfactant is selected from benzethonium chloride and benzalkonium chloride. 
     
     
         9 . A composition as claimed in  claim 1  having a pH from 4.5 to 5.5. 
     
     
         10 . A composition as claimed in  claim 1 , wherein the quaternary cationic surfactant is present at a level of from 0.5% to 2% by weight. 
     
     
         11 . A composition as claimed in  claim 1 , wherein the EDTA is present in the composition at a level of 0.2% to 1% by weight. 
     
     
         12 . A composition as claimed in  claim 1 , having a pH of about 5.5 to protect peri-wound tissue by not altering its pH balance. 
     
     
         13 . A process as claimed in  claim 12 , wherein the composition has a pH from 4.5 to 5.5. 
     
     
         14 . A process as claimed in  claim 12 , wherein the composition has a pH of about 5.5 to protect peri-wound tissue by not altering its pH balance. 
     
     
         15 . A process as claimed in  claim 12 , wherein the EDTA is present in the composition at a level of 0.2% to 1% by weight.