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Prostate Specific Membrane Antigen (PSMA) is a highly relevant target in nuclear medicine due to its overexpression in prostate cancer. The 68Ga/177Lu-PSMA-1 combination is a theranostic agent for the detection and treatment of tumors overexpressing the PSMA target. Specifically, 177Lu-PSMA-1 is used in the treatment of castration-resistant prostate cancer that is ineffective or intolerant to the latest generation of chemotherapy and/or hormone therapy. This radiopharmaceutical is manufactured in a radiopharmaceutical synthesizing unit and must pass a quality control where the radiochemical purity (RCP) is assessed prior to release of the batch. RCP evaluation is performed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Since there is no monograph for 177Lu-PSMA-1 in the European Pharmacopoeia, we validate the analytical methods according to the EANM recommendations adapted from ICH Q2. Specificity, linearity, accuracy, precision, intermediate precision, limit of quantification (LOQ) and robustness were described for HPLC and TLC in this study. The results obtained demonstrated the robustness and reliability of the HPLC and TLC analytical methods for the evaluation of the RCP of 177Lu-PSMA-1. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases, including fatal myocardial infarctions from atheromatous plaques, are the primary global mortality cause. Detecting stenotic atheromatous plaques is possible through coronary angiography, but vulnerable plaques with eccentric remodeling are undetectable with current diagnostic methods. Addressing this challenge, our group developed a radiopharmaceutical drug targeting vascular cell adhesion molecule 1 (VCAM-1), radiolabeled with technetium-99m. Given the absence of a monograph in the European Pharmacopoeia, and in order to draft the investigational medicinal product documentation, analytical methods had to be validated by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC) to determine the radiochemical purity (RCP) of 99mTc-cAbVCAM1–5. This study therefore presents the results of the validation of analytical methods obtained in this context. The method validation followed the European Association of Nuclear Medicine (EANM) recommendations adapted from ICH Q2(R1), ensuring conformity with specificity, accuracy, repeatability and intermediate precision, linearity, robustness, quantification limit (LoQ), and range criteria. Regarding the results of specificity, both HPLC and TLC methods demonstrated excellent separation of 99mTc-cAbVCAM1–5 from impurities 99mTcO4-. Accuracy results indicated recovery percentages within the range of 99.52–101.40% for the HPLC and 99.51–101.97% for TLC, ensuring reliable measurements for each concentration of 99mTcO 4 -. Precision of the methods was validated by assessing repeatability and intermediate precision. Linearity was determined over the usual concentrations range and the correlation coefficient was greater than 0.99 for both methods. The limit of quantification was measured by diluting the 99mTcO 4 - to obtain a signal-to-noise ratio of around 10:1. Under these conditions, we obtained an LOQ of 2.10 MBq/mL for HPLC and 2Mbq/mL for TLC. In conclusion, the analytical methods developed in this study comply with EANM recommendations. This therefore allows us to correctly assess the radiochemical purity of 99mTc-cAbVCAM1–5, a new radiotracer targeting inflammation in vulnerable plaques. • 99mTc-cAbVCAM1–5 is a new radiopharmaceutical targeting a marker of inflammation found in vulnerable atheromatous plaques in cardiac diseases. • A validation of the analytical method to evaluate the radiochemical purity (RCP) by HPLC and TLC was carried out. • Specificity, accuracy, precision, linearity, robustness, quantification limit, and range criteria were assessed. • The results demonstrate that the analytical methods are suitable for assessing the RCP of this new radiopharmaceutical. [ABSTRACT FROM AUTHOR]