Voltametric Determination of Zoledronic Acid in a Pharmaceutical Formulation

Objectives: The aim of this study is to study the electroactivity of zoledronic acid (ZOL), optimize the parameters affecting voltametric analysis of ZOL, and make a comparison between voltametric methods used to assay ZOL. Materials and
Methods: Three voltametric methods, cyclic voltammetry (CV), square wave voltammetry (SWV), and differential pulse voltammetry (DPV), were used to determine the concentrations of ZOL solutions (0.25-1.2 mg.mL-1). Britton-Robinson universal buffer solutions (BRB) were used as supporting electrolytes with a glassy carbon working electrode.
Results: The calibration plots were linear in the range from 0.20 to 1.2 mg.mL-1 for differential DPV and CV and from 0.09 to 1.2 mg.mL-1 for SWV. DPV showed the highest correlation coefficient R2 value of 0.993 and the lowest limit of detection (LOD) of 37.2 μg.mL-1. Furthermore, DPV exhibited the highest precision with the lowest relative standard deviations (RSD) values. For a commercial product of ZOL, DPV showed the best accuracy and precision with 102.32% recovery and 2.88% RSD.
Conclusion: ZOL is an electroactive compound. The pH of the BRB supporting the electrolyte is important for ZOL electroactivity. DPV is the recommended method for voltametric analysis of ZOL because of its high-performance regarding accuracy, precision, and LOD compared with other studied methods.