Patent ID: 8728508

Claim:
A method for the preparation of a cross-linked hydrophilic coating of a hydrophilic polymer on a substrate polymer surface of a medical device, said method comprising the steps of: (i) providing a medical device having a substrate polymer surface; (ii) providing a polymer solution comprising 1-20% by weight of a hydrophilic polymer, 0-5% by weight of additive(s), and the balance of said solution being a vehicle having at least one plasticizer with a solubility in water of at least 6 g/L, a boiling point above 210° C. at 760 mmHg, and a Hansen δH parameter of less than 20 wherein the plasticizer is selected from the group consisting of dimethyl sulfone, ethylene carbonate, glycerol diacetate, glycerol triacetate, hexomethylphosphoramide, isophorone, methyl salicylate, N-acetyl morpholine, propylene carbonate, quinoline, sulfolane, and triethyl phosphate; (iii) applying said polymer solution to said substrate polymer surface; (iv) evaporating at least a part of the vehicle from said polymer solution present on said substrate polymer surface at a temperature of 25°-100° C.; and (v) curing said hydrophilic polymer without rewetting the medical device, wherein said curing occurs by irradiation and is the only irradiation step in the process.