A soldering method achieving a high-strength joint between a solder and an nickelgold electroless plated surface is disclosed. In a further embodiment, herein is also disclosed a method of treating neoplastic disease, including cancer, comprising administering a pharmaceutical composition, the pharmaceutical composition comprising a highly concentrated aqueous solution of phenylacetate and in a 4:1 ratio, at an infusion rate of from 100 mLhr to 400 mLhr. After the extrusion step the crosslinking of the surface portion of the extruded article provided with the crosslinking additives is initiated by special initiation means.