Spectrophotometric determination of an antidiabetic drug glimepiride bulk and pharmaceutical formulations

A new, simple, precise, sensitive, accurate, and reproducible spectrophotometric method have been developed for the determination of Glimepiride in pure and dosage forms. Method is based on oxidation of the drug with 1,10 phenanthroline producing orange colored chromogen which is measured at 470 nm. Beer’s law is obeyed in the concentration range of  0.8-8.0 µg/mL for the developed method.The molar absorptivity and Sandell's Sensitivity are found to be9199.14 L mol-1cm-1and 0.053 µg/cm2 respectively. The regression equation for Glimepiride as found to bey= 0.0184X - 0.0013and the correlation coefficient for the regression line was 0.9943.  Different experimental parameters affecting the color development and stability of colored product are carefully studied and optimized. The developed method could be successfully applied to pharmaceutical formulations. The results obtained are in good agreement with those obtained using standard  method.