Solubilized medium for voltammetric determination of antimalarial drug hydroxychloroquine in synthetic urine sample

This present investigation reports a rapid electrochemical determination method for an antimalarial drug, hydroxychloroquine (HCQ) using in cationic surfactant. Different solubilized media including surfactants and organic solvents were screened and cetyltrimethylammonium bromide (CTAB) was selected. Electrochemical techniques, namely, Cyclic Voltammetry (CV), Square Wave Voltammetry (SWV) and Differential Pulse Voltammetry (DPV) were used to determine the peak current of analyte solution. The addition of CTAB to the HCQ solution resulted in the highest peak current among the studied solubilized systems. The current signal of HCQ observed due to its oxidation was found to be a function of drug concentration, pH of analyte solution and the type of additives. The DPV results were linear over the concentration range of 5-60 µg/mL with a limit of detection of 2.41 µg/mL. Excipients including important organic compounds and amino acids were used to study their interference in HCQ quantification. The proposed method was successfully applied for the determination of HCQ in spiked-synthetic urine samples. The results revealed good recovery values in the range of 89-104% for different concentrations of HCQ. Thus, the proposed method shows potential applicability for in vitro determination of the drug in urine sample.