Pharmaceutical compounds form the main sources of pollution, these substances now pose a serious environ mental threat due to the overuse of medications worldwide and their resistance to conventional wastewater treatment methods. In recent decades, the progressive development of ion-selective electrodes (ISEs), particu larly solid-contact ion-selective electrodes (SC-ISEs), aimed at enhancing potential stability and miniaturization for in situ and real-time analytical applications. The aim of this study is to provide portable, reliable, cost- effective, simple and ecofriendly methodology used to determine the activity of tolterodine tartrate in urine and wastewater by measuring the electrical potential related to its trace concentration. Solid-contact ion-se lective electrodes (SC-ISEs) represent sophisticated potentiometric sensors with remarkable proficiency in detecting a diverse array of ions, facilitating the surveillance of industrial operations, the assessment of envi ronmental contaminants, and the quantification of electrolytes for clinical evaluations. An advanced micro fabricated ion selective electrode is based on doping and casting of ZnO@α-Fe2O3 nanocomposite as electron transducer and decreasing potential drift from 8.0 mV/h to 1.0 mV/h on microfabricated electrode to improve the detection limit, electrode stability response and optimum slope 58.76 mV/decade in concentration range of 1.0 ×10 3–5.0 ×10 7 M, with lower detection limits 1.32 ×10 7 M and response time (7 ±1 s). Furthermore, Lean Six Sigma (LSS) is serving as a standard method for problem solutions and process optimization. The primary objective of this paper was quality improvement of tolterodine determination by reducing defects, waste elimination and processes variability to reach optimum response using LSS methodology.