Evaluation of boron-doped diamond electrode for simultaneous voltammetric determination of hydrochlorothiazide and losartan in pharmaceutical formulations

• Published in: Sensors and actuators. B, Chemical Chemical, 2013-11, Vol.188, p.263-270
• Main Authors: Santos, Michely Cristina Gardenal, Tarley, César Ricardo Teixeira, Dall’Antonia, Luiz Henrique, Sartori, Elen Romão
• Format: Article
• Language: English
• Subjects: Anodic pretreatment; BDD electrode; detection limit; drug formulations; electrodes; high performance liquid chromatography; hydrochlorothiazide; Hydrochlorothiazide determination; Losartan determination; oxidation; t-test; Voltammetry
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2013.07.025

A method for the simultaneous determination of hydrochlorothiazide (HCTZ) and losartan (LOS) in pharmaceutical formulations using differential-pulse voltammetry (DPV) was developed. Two very well-resolved and reproducible oxidation peaks of HCTZ and LOS, with separation of 0.23V, were obtained in Britton–Robinson (BR) buffer (pH 9.5) using an anodically pretreated boron-doped diamond electrode. Under the optimum analytical experimental conditions, the voltammetric method exhibited linear responses for simultaneous determination of HCTZ and LOS in the concentration range 3.0×10−6 to 7.4×10−5molL−1 for both compounds, with detection limits of 1.2×10−6molL−1 and 9.5×10−7molL−1, respectively. The proposed method was successfully applied in the simultaneous determination of LOS and HCTZ content in pharmaceutical formulations, whose accuracy was attested by good agreement of the results (paired t-test at a 95% confidence level) with those obtained using high performance liquid chromatography (HPLC).