The present invention relates to a method for modifying release of a therapeutically active agent from an elastomeric matrix, comprising providing a core comprising an elastomeric matrix and a therapeutically active agent; dipping the core to a coating solution of an elastomer, wherein the elastomer comprises 20-35 wt-% of a filler, calculated from the total amount of filler and elastomer; curing the dipped core to provide a coated core. In this method the dipping is provided as a continuous process by pulling the core through the coating solution, using a pulling speed suitable for providing a coating thickness of δ-IOO the filler is selected from silica, titanium dioxide, barium sulphate, carbon and mixtures thereof; the elastomer comprised in the core and the elastomer comprised in the coating solution are independently selected from poly(dimethyl) siloxanes, polyethylene vinyl acetates (EVAs), polyurethanes (PUs), polyhydroxyethyl methacrylates (PHEMAs) and polymethyl methacrylates (PMMAs).