Development and Evaluation of User-Friendly Single Vial DOTA-Peptide Kit Formulations, Specifically Designed for Radiolabelling with 68Ga from a Tin Dioxide 68Ge/68Ga Generator.

PURPOSE: This study was aimed to develop single vial 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-peptide kits to be used with fractionated eluates from a SnO2-based 68Ge/68Ga generator. PROCEDURES: Kits were formulated with 35 µg DOTA-Tyr3-Thre8-octreotide, DOTA-[Tyr3]-octreotide and DOTA-[NaI3]-octreotide (DOTATATE, DOTATOC and DOTANOC) and sodium acetate powder, vacuum-dried and stored at -20 °C for up to 12 months. Labelling of the kits was carried out with 2 ml 68Ga eluate. Comparative labelling was carried out using aqueous DOTA-peptide stock solutions kept frozen at -20 °C for up to 12 months. RESULTS: The quality of the kits was found to be suitable over a 1-year storage period (pH, sterility, endotoxin content, radiolabelling efficiency and radiochemical yields of 68Ga-labelled DOTA-peptides). Radiochemical yields ranged from 73 to 83 %, while those obtained from stock solutions from 64 to 79 %. No significant decline in kit labelling yields was observed over a 12-month storage period. CONCLUSION: The single vial kit formulations met the quality release specifications for human administration and appear to be highly advantageous over using peptide stock solutions in terms of stability and user-friendliness.