Stability evaluation of the drug substance is an integral part of the systematic approach to stability studies. Hence, three simple, sensitive and precise methods depending on two different techniques as UV spectrophotometry and chromatography were adopted for the task of stability indicating determination of sertaconazole (SER) in presence of its acidic degradation products. The first method is Zero-crossing first derivative ( 1 D) spectrophotometric one, which allows the determination of SER over a conc…