Convenient Formulation of ⁶⁸Ga-BPAMD Patient Dose Using Lyophilized BPAMD Kit and ⁶⁸Ga Sourced from Different...

⁶⁸Ga-BPAMD has recently emerged as one of the preferred radiopharmaceuticals for imaging of bone lesions due to its ability to produce high-resolution images and uncomplicated availability of ⁶⁸Ga, a positron emission tomography (PET) radionuclide, from commercial ⁶⁸Ge/⁶⁸Ga generators. The primary objective of this work is to develop freeze-dried BPAMD kit, for the easy and convenient formulation of ⁶⁸Ga-BPAMD patient dose at the hospital radiopharmacy. In addition, the kit should be compatible with ⁶⁸Ga, eluted using HCl of various molarities from the ⁶⁸Ge/⁶⁸Ga generators sourced from different suppliers.

Freeze-dried BPAMD kit, comprising 50 μg of BPAMD and 150 mg of HEPES, was prepared and evaluated using ⁶⁸Ga eluted from three different ⁶⁸Ge/⁶⁸Ga generators. Radiochemical purity (RCP) of ⁶⁸Ga-BPAMD was determined by both thin-layer chromatography and high-performance liquid chromatography studies. The maximum volume of ⁶⁸Ga, which can be added in the kit, was determined. The biological behavior of ⁶⁸Ga-BPAMD, prepared using the freeze-dried kit, was evaluated by both in vitro and in vivo studies. Clinical studies were also performed in limited number of patients suffering from metastatic bone cancer.

⁶⁸Ga-BPAMD could be prepared with >95% RCP using the freeze-dried BPAMD kit and ⁶⁸Ga eluted from ⁶⁸Ge/⁶⁸Ga generators obtained from three different suppliers. ⁶⁸Ga-BPAMD, prepared using the freeze-dried kit, exhibited adequate serum stability and ∼91% binding with the hydroxyapatite particles. Biodistribution studies in normal Wistar rats exhibited selective uptake of the agent in skeleton and fast clearance of the nonaccumulated activity through urinary route. Clinical studies in cancer patients showed excellent accumulation of the agent in bone lesions.

The preliminary studies exhibited the potential of the developed BPAMD kit toward its utilization for the PET scanning of skeletal metastases.