TiO<inf>2</inf> nanoparticles and ionic liquid platform for selective electrochemical determination of indacaterol in pharmaceutical formulations and human fluids: application to content uniformity

Abstract

The present work described the first voltammetric sensor for the estimation of indacaterol (IND) in the presence of its co-formulated drug glycopyrronium bromide. Indacaterol (IND) is used to treat chronic obstructive pulmonary disease, which is a major cause of morbidity and mortality worldwide so the quick analysis of minor concentrations of this drug is very important. Titanium(IV) oxide nanoparticles (TiO2-NPs) and the ionic liquid (IL) n-hexyl-3-methylimidazolium hexafluorophosphate were used for the new formulated carbon paste electrode. Other factors, such as the pH of the solution, the TiO2-NP concentration and the scan rate, were also optimized using cyclic voltammetry. Scanning electron microscopy, chronoamperometry and electrochemical impedance spectroscopy were utilized for determination of the character of the electrochemical sensor. Moreover, the electrochemical redox mechanism of IND at the proposed sensor was studied. Under the optimum conditions, the proposed TiO2-NP–IL–MCPE showed good linearity over a concentration range of 2.00 nM–200.00 mM using square wave voltammetry. The LOD was found to be 500 pM, indicating excellent sensitivity. Satisfactory recoveries of IND from pharmaceutical formulations, content uniformity tests and human plasma and urine were achieved, clearly revealing that the new sensor can be used in the clinical analysis of IND and in quality control laboratories.