Chromatographic determination of zonisamide, topiramate and sulpiride in plasma by a fluorescent ‘turn-on’ chemosensor

Abstract

Aim: Antiepileptics (AEDs) and antipsychotics are often coprescribed. Interactions between these drugs may affect both efficacy and toxicity. Therefore, drug monitoring is necessary for appropriate dosage adjustments. Materials & methods: Specific ‘turn-on’ chemosensor, 4-chloro-7-nitrobenzofurazan is used for selective and sensitive determination of two AEDs: zonisamide (ZON) and topiramate (TOP) with the antipsychotic sulpiride (SUL) in epileptic patients’ plasma followed by reversed-phase-HPLC separation without any interference. Results: Linear behavior was observed in the range of 0.1–3 μg/ml and 0.01–0.5 μg/ml for the AEDs and SUL, respectively, with LOD of 33, 46 and 4 ng/ml and LOQ of 86, 93 and 9 ng/ml for ZON, TOP and SUL, respectively. The proposed method was successfully applied for determination of different pharmacokinetic parameters of ZON and TOP, and for clinical monitoring of the three drugs in healthy volunteers following oral administration. Conclusion: The developed method is suitable for the routine therapeutic drug monitoring of these drugs.