**2.2 Technical parameters of radiopharmaceuticals and control methods**

One radiopharmaceutical product is characterized by several types of parameters, whose determination requires a very good knowledge of the physico-nuclear parameters of the radionuclide and the use of adequate methods and equipment for measurements. Their accepted limit values and methods of determination are described in international and national technical regulatory documents, such as the European Pharmacopoeia (2002). It is considered that the radiopharmaceuticals are products with a high pharmaceutical risk. The parameters are determined first of all in the radiopharmacy, which must dispose of control laboratories in full compliance with the requirements for Good Laboratory Practice (GLP) and accredited according to the international standard *"General Requirements for the Competence of Testing and Calibration Laboratories"*, ISO/IEC 17025:2005. Their determined values are confirmed by the national control laboratories, or are internationally recognized by conventions. Some parameters are controlled only in radiopharmacy, while others are compulsory for the nuclear medicine units, mainly when supplementary operations are carried. A detailed description of the requirements and of their accomplishment mode, regarding quality assurance in radiopharmaceutical measurement is presented in the document *Technical Report Series 454 (TRS 454)*, elaborated by the International Atomic Energy Agency (IAEA) (2006).

Three types of radiopharmaceuticals' parameters are generally defined and controlled: radiometrologic, physico-chemical and biological-microbiological parameters.
