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

Abstract

The prostate-specific membrane antigen (PSMA) represents an ideal biomarker for molecular imaging. Various PSMA-targeted radioligands are available for prostate cancer imaging. In this study, labelling of PSMA I&T with 68 Ga as well as validation of the radiochemical purity of the synthesis product by reverse phase radio 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 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-2 PSMA I&T, the developed method was validated to apply safely to patients. An excellent linearity was found between 1 μg/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 68 Ga-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 found comply with ICH requirements, thus demonstrating the accuracy and robustness of the method for routine clinical practice.

Development and Validation of Analytical Methods for Radiochemical Purity of 177Lu-PSMA-1

“…Many studies have already been published on the validation of analytical methods applied to radiopharmacy, in particular on the assessment of the radiochemical purity of specific radiopharmaceuticals. However, to date, none of these studies have combined an evaluation by HPLC and TLC [ 15 , 16 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Quality control of [177Lu]Lu-PSMA preparations using HPLC: effect of sample composition and ligand on recovery

“…Although we used a similar HPLC method (e.g. type of column, mobile phase, gradient, and run time) as described many times for different PSMA-based radiopharmaceuticals (Migliari et al 2017 ; Schottelius et al 2019 ; Wang et al 2018 ; Aalbersberg et al 2020 ; Fuscaldi et al 2014 ; Hooijman et al 2021 ; Iudicello et al 2021 ; Katzschmann et al 2021 ; Ugur et al 2021 ; European Pharmacopoeia 2021 ), we experienced the importance of sample composition on recovery. Almost none of the previously published studies mention the sample composition or dilution of the HPLC sample, and only a few studies reported recovery.…”

“…Other strategies to reduce the interaction of [ 177 Lu]Lu-PSMA-I&T to the column could be the use of other solvents or other HPLC columns. The mobile phase used in this study (based on TFA, acetonitrile and water) is commonly used for various PSMA variants (Migliari et al 2017 ; Schottelius et al 2019 ; Wang et al 2018 ; Aalbersberg et al 2020 ; Fuscaldi et al 2014 ; Hooijman et al 2021 ; Iudicello et al 2021 ; Katzschmann et al 2021 ; Ugur et al 2021 ; European Pharmacopoeia 2021 ). Different mobile phases, pH modifiers and solvents were evaluated but this did not prevent the interaction of PSMA-I&T with the HPLC column.…”

“…Radiodetection was at 20–1023 keV and UV detection at 220 nm. The method has been validated for the detection- and quantification limit, identification, carry-over, stability-indicating capacity, linearity, accuracy, precision, and robustness according to the current guidelines (Ugur et al 2021 ; Andel et al 2021 ) and standard operating procedures from our institute.…”

“…High-performance liquid chromatography (HPLC) coupled with a radio detector is the preferred semi-quantitative method for determining radiochemical purity of [ 177 Lu]Lu-PSMA (Gillings et al 2020 ). HPLC of radiolabeled PSMA-ligands (such as PSMA-I&T, PSMA-I&S, PSMA-I&F, PSMA-11, PSMA-1007, PSMA-617) is almost always performed with a reversed phase C18 column (generally with a pore size between 120 and 300 Å, a length of 150–250 mm, diameter of 3.0–4.6 mm, and a particle size of 3–5 µm, although many different brands are reported), with a gradient of acidified water and acetonitrile as the most common mobile phase (Migliari et al 2017 ; Schottelius et al 2019 ; Wang et al 2018 ; Aalbersberg et al 2020 ; Fuscaldi et al 2014 ; Hooijman et al 2021 ; Iudicello et al 2021 ; Katzschmann et al 2021 ; Ugur et al 2021 ; European Pharmacopoeia 2021 ).…”