Design of Green Polypyrrole-based Solid-contact Ion-selective Sensors for Determination of Antihypertensive Drugs in Combined Dosage Forms and Spiked Human Plasma

Abstract

Solid contact ion-selective electrodes (SC-ISEs) have created a new, promising field in pharmaceutical and biological analysis, recognized as an energy-saving, straightforward, and environmentally friendly technique. Hence, in the present study, miniaturized solid-contact ion-selective sensors have been fabricated as well as designed for the simultaneous in-line quantification of cationic amlodipine (AML) and anionic valsartan (VAL) in binary and ternary mixtures with hydrochlorothiazide (HCT). A screen-printed carbon electrode and a PVC polymer ion sensing membrane are the essential core of the suggested sensors. A conductive polymer interlayer of polypyrrole (PPy) was utilized as an ion-to-electron transducer embedded between the carbon electrode and the polymer ion sensing membrane. The influence of PPy resulted in a reduction of potential drift to <500 μV/h and enhanced electrode stability. The performance of the suggested sensors was evaluated in accordance with IUPAC guidelines. The sensors proposed for both drugs presented stable, linear, as well as rapid responses over wide AML and VAL concentration ranges (3.0 × 10−6 to 1.0 × 10−3 M and 1.0 × 10−5 to 1.0 × 10−3 M, respectively). The fabricated potentiometric sensors were also implemented to determine the studied drugs in spiked human plasma without requiring any sample pre-treatment or derivatization. Additionally, the investigated method was also thoroughly evaluated for its greenness using a variety of green metrics.