Development of a freeze-dried radiopharmaceutical kit for dopamine transporters imaging

Introduction: 99mTc-TRODAT-1 is a promising new radiopharmaceutical with the potential for routine use as the radiopharmaceutical for dopamine transporters scintigraphy as far as its image quality and daily availability are concerned. Here we describe the development of a freeze-dried kit formulation based on the tricine exchange labeling approach for the preparation of this radiopharmaceutical in a clinical setting. Methods: A freeze-dried formulation contained of TRODAT-1, tricine, SnCl2 and manitol was prepared. Labeling was performed by addition of 1480 MBq 99mTc sodium pertechnetate in a total volume of 2 mL and incubation for 15 min in a boiling water bath. Radiochemical analysis involved ITLC and HPLC methods. The stability of radioconjugate was checked in the presence of human serum at 37 °C up to 24 h. Results: 99mTc-TRODAT-1 was prepared with a radiochemical purity of >95% and a high stability up to 24 h of the final preparation, and retained biological activity. Conclusion: The developed kit formulation forms the basis for further clinical evaluation of this promising new radiopharmaceutical.