High specific activity is an important requirement for the radiotracer for most applications in biology and medicine. Investigations were carried out to prepare high specific activity As-77, Tc-99m and Re-188 which have potential in radiotherapy.Many imaging and therapeutic applications are dependent on the use of concentrated solution of radionuclides. Concentrated solutions of radionuclide provide good labeling yield of molecules. In this regard the concentration techniques developed in this study for 99mTc, and 188Re will certainly increase the purity of radionuclide as well as ensure the optimum use of generator systems in their working life time. The Concentrated solution of these radionuclides were successfully employed for therapeutic radiopharmaceuticals