Validation of HPLC method for the determination of chemical and radiochemical purity of a $^{68}Ga-labelled EuK-Sub-kf-(3-iodo-y-) DOTAGA$

Abstract

The prostate-specific membrane antigen (PSMA) represents an ideal biomarker for molecular imaging. Various PSMAtargeted radioligands are available for prostate cancer imaging. In this study, labeling of PSMA I&T with $^{68}Ga$, as well as validation of the radiochemical purity of the synthesis product by reverse phase radio high-performance liquid chromatography (HPLC) method are intended. Since the standard procedure for the quality control (QC) was not available, definition of chemical and radiochemical purity of $^{68}Ga$-PSMA I&T was carried out according to the Q2 (R1) ICH guideline. The standard QC tests were analyzed with Scintomics 8100 radio-HPLC system equipped with a radioactivity detector. The method was evaluated in terms of linearity, precision and accuracy, LOQ, robustness parameters, and specificity. To assess the radiochemical and chemical purity of $^{68}Ga$-PSMA I&T, the developed method was validated to apply safely to patients. An excellent linearity was found between 1μg/mL and 30 μg/mL, with a limit of detection and limit of quantitation of 0.286 μg/mL and 0.866 μg/mL, respectively for 68Ga-PSMA I&T. The recovery was 96.8 ± 3.8%. The quality control of the final product was performed many times with validated radio-HPLC method and was found to comply with ICH requirements, thus demonstrating the accuracy and robustness of the method for routine clinical practice.