Validation of an HPLC method for determination of chemical purity of [¹⁸F]fluoromisonidazole ([¹⁸F]FMISO)

[¹⁸F]Fluoromisonidazole ([¹⁸F]FMISO) is a nitroimidazole derivative labelled with fluorine-18 that selectively binds to hypoxic cells. It has been shown to be a suitable PET tracer for imaging hypoxia in tumors as well as in noncancerous tissues. [¹⁸F]FMISO was prepared using a TRACERlabMX_FDG® module (GE) with cassettes, software sequence and reagents kits from ABX. In this work, we aimed to develop and to validate a new high performance liquid chromatography (HPLC) method for determination of chemical purity of [¹⁸F]FMISO. Analyses were performed with an Agilent chromatograph equipped with radioactivity and UV detectors. [¹⁸F]FMISO and impurities were separated on a C18 column by gradient elution with water and acetonitrile. Selectivity, linearity, detection limit (DL), quantification limit (LQ), precision, accuracy and robustness were assessed to demonstrate that the HPLC method is adequate for its intended purpose. The HPLC method showed a good precision, as all RSD values were lower than 5%. Robustness was evaluated considering a variation on parameters such mobile phase gradient and flow rate. Results evidenced that the HPLC method is validated and is suitable for radiochemical purity evaluation of [¹⁸F]FMISO, considering operational conditions of our laboratory. As an extension of this work, other analytical methods used for [¹⁸F]FMISO quality control should be evaluated, in compliance with good manufacture practice. (author)