Synthesis, Characterization, and Radiolabeling of Heterocyclic Bisphosphonate Derivative as a Potential Agent for Bone Imaging

Abstract

1-Hydroxy-2-(2-pyridyl)ethanedisphosphonic acid monosodium salt (HPEDP) was prepared and labeled with ^99mTc using two different reducing agents: SnCl₂·2H₂O and NaBH₄; NaBH₄ gave better results. The radiochemical purity of ^99mTc(NaBH₄)-HPEDP was 96 ± 4%, and the complex was stable in vitro for 6 h. The in vivo biodistribution studies performed in mice show highly selective uptake of the labeled compound in the skeletal system and rapid elimination via the urinary pathway. The maximum bone uptake was 32.3 ± 2.1% ID/organ.