The present invention provides a novel process for preparing Form 1 ranitidine hydrochloride by crystallization from at least one C1-C6 alkanol. It provides a method for manufacturing an antenna for percutaneous acute hyperthermia microwave applications of the monopole or dipole co-axial type provided with trap, commonly called choke, for blocking the propagation of the backwards reflecting wave towards the generator. The buffer brush contains a core having a first side and a second side and the brush extends racially from the surface of the core.