t-Butyl calixarene/Fe2O3@MWCNTs composite-based potentiometric sensor for determination of ivabradine hydrochloride in pharmaceutical formulations
Fatehy M. Abdel‐Haleem, Eman Gamal, Mahmoud S. Rizk, Rasha M. El Nashar, Badawi Anis, Hussam M. Elnabawy, Ahmed S.G. Khalil, Ahmed Barhoum
Abstract
Ivabradine hydrochloride (IVB) has shown high medical importance as it is a medication for lowering the heart rate for the symptomatic chronic heart failure and symptomatic management of stable angina pectoralis. The high dose of IVB may cause severe and prolonged bradycardia, uncontrolled blood pressure, headache, and blurred vision. In this study, a highly sensitive carbon-paste electrode (CPEs) was constructed for the potentiometric determination of IVB in pharmaceutical formulations. t-Butyl calixarene (t-BCX) was used as an ionophore due to its ability to mask IVB in the cavity via multiple H-bonding at the lower rim, as estimated quantitatively by the sandwich membrane method (Log β ILn = 8.62). Besides, the use of multi-walled carbon nanotubes decorated with Fe 2 O 3 nanoparticles (Fe 2 O 3 @MWCNTs) as an additive for the paste electrode significantly improved the detection limit of the sensor up to 36 nM, with Nernstian response of 58.9 mV decade −1 in the IVB linear dynamic range of 10 −3 –10 −7 M in aqueous solutions. The constructed sensors showed high selectivity against interfering species that may exist in physiological fluids or pharmaceutical formulations (e.g. Na + , K + , NH 4 + , Ca 2+ , Mg 2+ , Ba 2+ , Fe 3+ , Co 2+ , Cr 3+ , Sr 2+ , glucose, lactose, maltose, glycine, dopamine, and ascorbic acid). The sensors were successfully employed for IVB determination in the pharmaceutical formulations (Savapran®). • Electrochemical sensor was constructed for IVB determination in pharmaceutical formulation. • t-Butyl calixarene was used as ionophore for masking IVB via multiple H-bonding. • MWCNTs having twenty walls were prepared by chemical vapor deposition. • Fe2O3@MWCNTs was employed to increase the electrodes sensitivity. • Best constructed sensor showed high selectivity against the interfering species.