Hydrogel composition based on co-polymer carrying multiple pendant sulphonic groups for use as a wound dressing
The present invention provides a hydrogel composition, preferably for the treatment of wounds, comprising a hydrophilic co-polymer carrying multiple pendant anionic groups, wherein the polymer is derived from a first monomer and a second monomer, wherein both monomers have an octanol:water partition coefficient LogP value of less than 0, and, the LogP value of the first monomer is greater (more positive) than the second monomer. The difference between the LogP value for the two monomers is preferably less than 2. The weight ratio (w/w) of the first monomer/second monomer in the hydrogel composition is preferably equal to or more than about 1. The pendant anionic groups may be sulphonyl groups, e.g. sulphonic acid groups or salts thereof. The anionic group in both first and second monomers may be in salt form and the counterion for both monomers is preferably the same.
1. A hydrogel composition for the treatment of wounds, comprising a hydrophilic copolymer carrying multiple pendant sulphonic groups,
wherein the copolymer is derived from a first olefinically unsaturated sulphonic acid monomer and a second olefinically unsaturated sulphonic acid ester monomer,
wherein both monomers have an octanol:water partition coefficient (LogP) value of less than 0,
wherein the first monomer has a LogP value greater (more positive) than the second monomer, the molar ratio of the first monomer/second monomer in the hydrogel is between 1 to 3, and both the first and second monomers comprise a pendant sulphonic group in salt form and the counterion for both monomers is sodium, and
wherein the first monomer is acrylic acid (3-sulphopropyl) ester (NaSPA) and the second monomer is 2-acrylamido-2-methylpropanesulphonic acid (NaAMPS).
2. A hydrogel composition according to claim 1 , wherein the molar ratio of the first monomer/second monomer in the hydrogel is between 2 to 3.
3. A hydrogel composition according to claim 1 , wherein the molar ratio of the first monomer/second monomer in the hydrogel is between 2.4 to 3.