Innovative Potentiometric Quantification of Flutamide Using Novel Ion-Selective Electrodes with Sulfonphthalein Dyes

Two potentiometric sensors, referred to as ion-selective electrodes (ISE)-A and ISE-B, were constructed and validated to quantify the flutamide (FA) in drug formulations, extended to analyse human urine samples infused with drugs. Bromocresol green and bromophenol blue were used as ion-pair complexing agents in the construction of ISE-A and ISE-B, respectively. Dibutyl phthalate served as a plasticizer within a polyvinyl chloride matrix, with tetrahydrofuran as the solvent. The methods demonstrated linearity over the ranges of 2.5 x 10-6 to 2 x 10-3 M and 5 x 10-6 to 1.8 x 10-3 M for ISE-A and ISE-B, respectively. The Nernstian slop of 58.8 ± 0.96 and 62.11 ± 0.83 were exhibited by the proposed methods employing ISE-A and ISE-B, respectively, within a response time of 25 seconds and were effective for the analysis of FA over a period of 52 days within a pH range of 1.0 to 4.2. The coefficient of determination (R2) was very close to one, indicating an excellent fit between the actual and measured data. For ISE-A, the computed limits of detection and quantification were 0.82 x 10-6 M and 2.45 x 10-6 M, respectively, and 1.64 x 10-6 M and 4.86 x 10-6 M for ISE-B. The ICH recommendations were followed during the validation process, which evaluated the methodologies' robustness, ruggedness, sensitivity, accuracy, precision, and selectivity.