A method and device for local delivery of water-soluble or water-insoluble therapeutic agents to the surface of a normal or diseased body lumen is disclosed. An expandable structure of a medical disposable device, such as a balloon of a balloon catheter, is coated with an amphiphilic polymer coating comprising a therapeutic agent and an amphiphilic polymer or co-polymer. The medical disposable device is inserted into a body lumen, and expanded to contact the amphiphilic polymer coating against the body lumen. The total solubility of the polymer or co-polymer in vivo prevents any embolic hazard associated with the amphiphilic polymer coating.