ABSTRACT
In this study, simple, sensitive and reliable spectroscopic methods (absorbance ratio and Vierordt) were compared with HPLC method developed for quantitative determination of spironolactone (SPL) and hydrochlorothiazide (HCT) in commercial tablets.
260 nm was chosen as the isosbestic point in the absorbance ratio method. For Vierordt method; A11 values were calculated at 242 and 269 nm for both substances and used for quantitative analysis of HCT and SPL in its binary mixture. Linearity ranges for HCT and SPL was 2-15 ug/mL and 2-12 ug/mL respectively for both methods. The relative standard deviations for absorbance ratio and Vierordt-methods were found to be 1.58 % and 1.32 % for HCT, 1.26 % and 1.52 % for SPL respectively. In HPLC method, HCT, SPL and Mefrusid (MFS) as an internal standard were determined by isocratic system using water-methanol-phosphate buffer (pH 3.0 ± 0.1) (71:25:4 v/v/v) as mobile phase and with Luna.C18 column. Linear concentration range was 5-25 ug/mL, 2-15 ug/mL for HCT and SPL respectively, and the relative standard deviations were found to be 1.39 % for HCT and 1.44 % for SPL respectively. Therefore, it is concluded that two spectroscopic methods and HPLC method can be used in routine simultaneous quantitative analyses ofHCT-SPL in commercial tablets.