Evaluation of the EDTMP freeze-dried kit for preparation of bone-seeking radiopharmaceuticals

High affinity of EDTMP to skeleton and to osteoblastic bone metastases, as well as a considerable high stability of many EDTMP chelates has caused the efforts on application of this bone-seeking ligand as the in vivo carrier of various radionuclides intended both for therapy and diagnosis of osteoblastic lesions. Previously, we have developed the freeze-dried kit for formulation of EDTMP radiopharmaceutical chelates with the 'pain palliation' radio-lanthanides e.g.: 153Sm and 177Lu, likewise with 'diagnostic' 99mTc. This work aims to evaluate some properties of the developed kit and radiopharmaceutical preparations in accordance to fulfil quality and safety criteria dictated for medicinal product for human use. 177Lu-EDTMP formula proposed for patient treatment is as close as justified to the originally approved formula of 153Sm-EDTMP in terms of ligand quantity, ligand molar excess over the Lu metal, specific activity of 177Lu and the Ca+ and Na+ cations content. The kit contains 35 mg of EDTMPxH2O and Lu which should correspond to about 50 microgram of 153Sm in Quadramet formulation. Freeze-dried kits were prepared according to the optimized formulation and then send to co-operating laboratories for pre-clinical evaluation. (author)