Radiopharmaceuticals analysis: Biomedical chromatography applications

Radiopharmaceutical synthesis methods use relatively large amounts of reagents, necessitating the use of high-resolution and high-capacity chromatographic methods. Furthermore, purification is required prior to the formulation of radiopharmaceuticals for injection to remove various impurities. However, for routine injectable production, radio-thin layer chromatography (i-TLC) is preferred because of short time runs and user friendliness. The problem with i-TLC is that TCL plates are not as efficient as high performance liquid chromatography (HPLC) columns and are also limited to radioactive detection, so impurities are frequently missed. In this study, the aim was to develop and validate shorter liquid chromatography methods utilising Gabi, a diode array (UV-VIS), and an evaporative light scattering detector (ELSD) all in conjunction. The analytes of interest in this study were 68Ga- Fapi, 68Ga-Dotatate, and 68Ga-prostate-specific membrane antigen-617. Degradation of chelators and the introduction of impurities can occur during radiopharmaceutical synthesis. If the sample contains chromophores, the UV-VIS detector can detect them all. The Gabi is capable of detecting all substances containing radionuclides that emit gamma rays. All substances that can diffract light can be detected by the ELSD detector. In this study, it was demonstrated that a simple (5–10 min) HPLC analytical method with three simultaneous detection systems can be more profitable than the conventional iTLC method for determining the purity of radiopharmaceuticals. (authors)