Synthesis of [18F]rufinamide as a radiotracer for epileptic brain imaging

Abstract

Epilepsy is a multifactorial neurological disorder characterized by recurrent, unprovoked seizures. Although various diagnostic approaches are available, no single technique serves as a gold standard. Radiotracer-based positron emission tomography (PET) offers a non-invasive strategy for localizing epileptic foci. However, the currently available tracers have limited specificity and pharmacokinetic performance. In this work, report the radiosynthesis and preliminary evaluation of [¹⁸F]rufinamide as a potential PET tracer for epilepsy imaging. Microwave-assisted (µE) radiosynthesis (120 °C, 20 min) afforded quantitative conversion with a total synthesis time of 40 min from the end of bombardment (EOB), and a two-step procedure completed with 20 ± 5%, radiochemical yield and >95% radiochemical purity. The physicochemical profiling revealed a lipophilic nature (log D_7.4) and high plasma protein binding (82.5 ± 2.1%). PET imaging and biodistribution studies in normal Wistar rats confirmed brain uptake and renal clearance. These findings demonstrate that [¹⁸F]rufinamide possesses favorable radiochemical and pharmacological characteristics, supporting its potential as a novel PET probe for non-invasive imaging of epileptic brain regions.