The invention relates to a process for producing biomedical articles, in particular, silicone hydrogel contact lenses having durable hydrophilic chitosan coating. The chitosan coating is covalently attached to the medical device by performing a crosslinking reaction between chitosan and the carboxylic groups on the surface of a medical device directly in a sealed package during autoclave. The coated biomedical articles obtainable by the process of the invention have desirable characteristics regarding adherence to the substrate, durability, hydrophilicity, wettability, biocompatibility and permeability and are thus especially useful in the field of ophthalmic devices.