Validation of chromatographic methods, TLC and HPLC, to quantify known radiochemical impurities and the radiochemical purity the radiopharmaceutical [177Lu]Lu-PSMA I&T

The Energy and Nuclear Research Institute (IPEN) is studying the production of the radiopharmaceutical [¹⁷⁷Lu]Lu-PSMA I&T, in accordance with the good manufacturing practices recommended by the National Health Surveillance Agency (ANVISA), to be used in the therapy of prostate cancer. This work aims to validate chromatographic methods, Thin-Layer Chromatographic (TLC) and high-performance liquid chromatography (HPLC), to determine the radiochemical purity (RCP) of the product. The entire validation process of this work was based on ANVISA's RDC 166, 2017 and the Guide 10, version 1, 2017, guided the statistical treatments adopted. With the selectivity study we can observe that the presence of impurities or excess excipients in the sample does not interfere with the quantification of the product. The proposed methods were linear with linear correlation coefficients (r) above 0.99. The precision and repeatability presented relative standard deviation values lower than specified (RSD <5 %). The small controlled variations in the method suggested for the robustness test also did not affect the radiochemical purity of the product. In view of the results and in accordance with the criteria established by the National Health Surveillance Agency (ANVISA), the two chromatographic methods were validated in accordance with RDC 166, 2017, proving to be selective, precise, linear and robust. The validation of TLC and HPLC methods enables their application in the batch release routine of the new radiopharmaceutical at Radiopharmacy Center of IPEN.