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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.

An efficient and fast microwave-assisted extraction (MAE) technique was developed for extracting trigonelline as an indicative biomarker for the quality control of Trigonella foenum-graecumseeds. The MAE procedure was optimized and compared with other conventional extraction techniques. The optimal conditions of MAE were 50% methanol as solvent, solid—liquid ratio 1:20 g mL−1, irradiation power 40%, and two extraction cycles, 3 min each. The proposed extraction technique produced a maximum yield of 7.89 mg g−1trigonelline in 6 min which was 1.28 and 2.20 times more efficient than 3 h of heat reflux and 15 h of maceration extraction, respectively. Furthermore, rapid high-performance thin-layer chromatographic and high-performance liquid chromatographic methods for the quantification of trigonelline were established and validated. The methods were found to be simple, sensitive, precise, accurate, and specific for the estimation of trigonelline in T. foenum-graecumseeds extract and overcame disadvantages of previously published methods.