A method of forming a polyurethane foam suitable for use as a wound-contacting layer, said method comprising: mixing 1 part by weight of an isocyanate-capped prepolymer having from 0.5 to 1.2 meq NCO groups/g with from 0.4 to 1.0 parts by weight of water in the presence of from 0.05 to 0.4 parts by weight of a C1 to C3 monohydric alcohol to form a foamed product; followed by treating the foamed product with a dispersion of a therapeutic agent and drying the treated foamed product. Also provided are medicated polyurethane foams obtainable by the method of the invention, and wound dressings comprising such foams.