HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC DETERMINATION OF GLIMEPIRIDE AND TIMOLOL IN PHARMACEUTICAL FORMULATIONS USING BRITTON -ROBINSON BUFFER IN MOBILE PHASES

Actually, Glimepiride (GLI) and Timolol (TIM) are analysed by several analytical techniques such as HPLC, Uv Vis and electrochemical methods, but in this study these compounds were determined by use Britton-Robinson (B-R) buffer pH3 in mobile phases as a new work. 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´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 analytical determined using C-18 (5µm) with UV detector at 254 nm and 1.00 mL min-1 flow rate by 10 µL injection volume. The calibration curves for GLI and TIM were studied over the range 1×10-4 to 1×10-3 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 5×10-4 mol L-1 of GLI and TIM , yielded good results for ten HPLC measurements with relative standard deviations RSD% were 0.43 and 1.1%, and good stability observed. The developed HPLC was applied to determine of GLI and TIM in pharmaceutical formulations with mean recoveries 103% ±0.71 and 99% ±1.0, respectively.