Enhancing the Sustainability of Eco-friendly Potentiometric Ion Selective Electrodes for Stability-Indicating Measurement of Ethamsylate: Application in Bulk and Pharmaceutical Formulations

Through the use of sustainable and green chemistry concepts, scientists need to decrease waste, conserve energy, and develop safe substitutes for hazardous compounds, all for protecting and benefiting society and the environment. Four novel eco-friendly ion selective electrodes (ISE) were created to determine Ethamsylate (ETM) in bulk powder and different pharmaceutical formulations. The present electrodes were fabricated and evaluated to clearly distinguish ETM from a variety of inorganic, organic ions, sugars, some common drug excipients and the degradation product, hydroquinone (HQ) of ETM, and thus could be used for stability-indicating methods. The electrodes fabrication was based on 2-nitrophenyl octyl ether (NPOE) that was employed as a plasticizer in electrodes 1, 2, and 3 within a polymeric matrix of polyvinyl chloride (PVC) except for electrode 4, in which dibutyl sebacate was used as a plasticizer. Electrodes 1 & 2 were fabricated using tetra dodecyl ammonium bromide as an anionic exchanger and adding 4-sulfocalix-8-arene as an ionophore only to electrode 2, but electrode 1 prepared without incorporation of an ionophore. The fabrication of electrodes 3 & 4 was based on ethamsylate-tetraphenylborate (ETM-TPB) as an ion-association complex in a PVC matrix. The environmental sustainability was assessed using Green Analytical Procedure Index (GAPI), and Analytical Greenness Metric for Sample Preparation (AGREEprep). Electrodes 1 & 2 had linear dynamic ranges of (10-1-10 -5) and (10-1-10 -4) respectively, with a Nernstian slope of 49.6 and 53.2 mV/decade, respectively. Electrodes 3 & 4 had linear dynamic ranges of (10-1-10 -4), with a Nernstian slope of 43.9 and 40.2 mV/decade, respectively. The generated electrodes' selectivity coefficients showed good selectivity for ETM. The utility 4-sulfocalix-8-arene as ionophore had a significant influence on increasing the membrane sensitivity and selectivity of electrode 2 compared to other electrodes.