Development and Validation of an HPLC Method to Determine Chemical and Radiochemical Purity of [18F]Florbetazine Injection

[¹⁸F]Florbetazine injection, a radiotracer that could target Aβ plaques and achieve diagnosis of Alzheimer's disease (AD), is a novel positron emission tomography (PET) imaging agent currently in the investigational new drug (IND) application stage. The active ingredient of [¹⁸F]Florbetazine injection, [¹⁸F]Florbetazine, is a diaryl-azine derivative. Chemical and radiochemical purity is critical quality attributes (CQAs) for [¹⁸F]Florbetazine injection, and thus, we have developed and validated a relevant HPLC method. This study describes the specificity, linearity, accuracy, repeatability, and limit of quantification (LOQ) of the HPLC method. The stability of three sample batches was investigated using the established method. The validation results demonstrated the accuracy, precision, and sensitivity of the method, making it suitable for implementation as part of the quality control (QC) process for [¹⁸F]Florbetazine injection. The stability of three sample batches revealed a decrease in concentration and radiochemical purity over 10 h. However, all samples maintained a radiochemical purity of over 90% after 10 h. The results provided a foundation for establishing quality standards for [¹⁸F]Florbetazine injection. The same methodology employed in this study could be applied and modified for QC protocols of other ¹⁸F-labeled radiopharmaceuticals.