Application of Vierodt’s and Absorption Correction Spectrophotometric Methods for Estimation of Rosiglitazone Maleate and Glimepiride in Tablets

Two new UV-spectrophotometric methods have been developed for simultaneous estimation of rosiglitazone maleate and glimepiride in tablets. The first method was based on application of vierodt’s method which involves the formation and solving of simultaneous equations at 247.0 and 228.0 nm, as absorbance maxima of rosiglitazone maleate and glimepiride, respectively. The second method employed was absorption correction method which involves direct estimation of rosiglitazone maleate at 311.5 nm, as at this wavelength glimepiride has zero absorbance and shows no interference. For estimation of glimepiride, corrected absorbance was calculated at 228.0 nm due to the interference of rosiglitazone maleate at this wavelength. Calibration curves were linear with correlation coefficient between 0.99-1.0 over the concentration range of 2-20 μg/mL for both the drugs. The mean percent recovery was found in the range of 99.41-99.80 and 100.36-100.52 for vierodt’s method and 99.18-99.80 and 99.64-99.92 for absorption correction method, for rosiglitazone maleate and glimepiride, respectively. The results of analysis were validated statistically and proven to be rugged. The proposed methods are simple, rapid, accurate, precise, economical and can be used successfully in the quality control of pharmaceutical formulations and routine laboratory analysis.