Background
Current analytical
Conclusions
HPLC-ICP-MS is a robust, sensitive and radiation-free technique to characterize the pharmacokinetics and metabolism of imaging probes.
Methods
Two known peptide-DOTA conjugates were chelated with natGa and natIn. Limit of detection of HPLC-ICP-MS for 69Ga and 115In was determined. Rats were administered 50-150 nmol of Ga- and/or In-labeled probes, blood was serially sampled, and plasma analyzed by HPLC-ICP-MS using both reverse phase and size exclusion chromatography.
Results
The limits of detection were 0.16 pmol for 115In and 0.53 pmol for 69Ga. Metabolites as low as 0.001 %ID/g could be detected and transchelation products identified. Simultaneous administration of Ga- and In-labeled probes allowed the determination of pharmacokinetics and metabolism of both probes in a single animal. Conclusions: HPLC-ICP-MS is a robust, sensitive and radiation-free technique to characterize the pharmacokinetics and metabolism of imaging probes.