Abstract
Usually, the analytical techniques used to analyze Glimepiride (GLI) and Timolol (TIM) are HPLC, UV-Vis and electrochemical methods. In this study, we developed a new procedure for its determination by using Britton-Robinson (B-R) buffer pH3 in mobile phases. B-R pH3 : Acetonitrile : Water : Methanol (10 : 30 : 10 : 50 % v/v/v/v) and B-R pH3 : Acetonitrile : Methanol (30 : 15 : 55 % v/v/v), were used as mobile phases for chromatographic studies of GLI and TIM respectively. 1.0. 10(-3) mol L-1 of GLI and TIM were prepared by dissolving the suitable weight of analyte in methanol and distilled water respectively, in 50 ml volumetric flask. GLI and TIM were HPLC separated from interferences and analytically determined using C-18 (5 mu m) with UV detector at 254 nm and 1.00 mL min(-1) flow rate by 10 mu L injection volume. The calibration curves for GLI and TIM were studied over the range 1.0x10(-4) to 1.0x10(-3) mol L-1 (correlation coefficient =0.994, n=6) for GLI and (correlation coefficient =0.996, n=6) for TIM. The HPLC reproducibility and stability were evaluated for 5.0x10(-4) mol L-1 of GLI and TIM, yielded good results for eight measurements with relative standard deviations RSD% were 0.44 and 1.43%, and good stability is observed. The developed HPLC is applied in order to determine of GLI and TIM in pharmaceutical formulations with mean recoveries 103% +/- 0.71 and 99% +/- 1.00, respectively.