Electrochemical determination of selected antihypertensive and antituberculosis drugs at a tyrosine-modified electrode†
A simple and sensitive electrochemical method was proposed for the determination of hydralazine hydrochloride (HDH), isoniazid (ISN), ethambutol hydrochloride (EBH) and pyrazinamide (PZM). For the first time, a tyrosine (Tyr)-modified glassy carbon electrode (GCE) was employed for the determination of HDH, ISN, PZM and EBH by the differential pulse voltammetric (DPV) technique. The proposed modified electrode showed strong electrocatalytic activity towards the above-mentioned drugs with a higher peak enhancement than that of an unmodified electrode. The practicality of the proposed electrode for the detection of HDH, ISN, PZM and EBH in human urine and blood serum samples was successfully demonstrated using the DPV technique. The applicability of the proposed method was verified with commercially available pharmaceutical tablets and the obtained results were in good agreement with the claimed label amounts of the tablets. From these results, it is clearly evident that the proposed electrode shows good catalytic activity towards HDH, ISN, PZM and EBH. In addition, this method could be used in the future for the accurate detection of HDH, ISN, PZM, and EBH in clinical and pharmaceutical industries.