Patent ID: 7696259

Claim:
A durable hydrophilic biocompatible coating formulation for a medical device having abstractable hydrogen radicals, the formulation including a hydrophilic polymeric component comprising at least two polymeric species of differing molecular weights, an unsaturated hydrophilic monomer capable of free-radical polymerisation in the presence of a radical and a UV activatable compound capable of abstracting hydrogen radicals from the surface to be coated and from a polymeric species of the hydrophilic polymeric component so as to initiate and promote the cross-linkage of the monomer to the surface and of the monomer or a propagating monomer chain to a polymeric species of the polymeric component, and a suitable solvent, wherein said formulation is suitable for coating on an implantable biomedical device with only one curing step, wherein at least one polymeric species comprises a relatively lower molecular weight polymer and at least one polymeric species comprises a relatively higher molecular weight polymer, and wherein the ratio of lower molecular weight polymer to higher molecular weight polymer is between about 1:3 and 1:2, and wherein the relatively lower molecular weight polymer has molecular weight in the range of 40 kDa to 100 kDa and the relatively higher molecular weight polymer has a molecular weight in the range of 100 kDa to 1500 kDa, wherein the coating comprises a first layer comprising the monomer capable of covalently attaching to the surface of the biomedical device and a second layer comprising a polymer that is covalently linked to the monomer layer.