in accordance with the present invention , there are provided prosthetic articles having polyurethane coatings with biologically active compounds incorporated within the interstices of the polymer . methods for the preparation of such articles are also provided . thus , a polyurethane coating is applied to a prosthetic article , the coating then swelled so that substantial quantities of biologically active compounds can be incorporated within the interstices of the polymer . upon long term exposure of a prosthetic article of the invention to physiological conditions , the biologically active compound is slowly released by the treated polymer . the biologically active compound is , therefore , released only at the site where it is desired , i . e ., where the prosthetic article is positioned .