A Stability-indicating HPLC Method for the Simultaneous Determination of Mebeverine Hydrochloride and Chlordiazepoxide in Commercial Tablets

A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed which can separate and accurately quantitate Mebeverine hydrochloride (MEB) and Chlordiazepoxide (CPZ) in commercial tablets. The method has shown adequate separation for MEB and CPZ from their degradation products and main impurities of CPZ whether in pure forms or in commercial tablets. A gradient mobile phase system consisting of (A) water and (B) methanol was used with Phenomenex (R) Luna C18 analytical column (250mm x 4.6mm i.d., 5 mu m ps). Quantitation was achieved with UV detection at 254 nm, based on peak area. MEB and CPZ were subjected to acidic, basic hydrolysis and oxidative degradation to apply stress conditions. The linearity of the proposed method was investigated in the range of 40-130 mu g ml(-1) (r = 0.9987) for MEB and 8-22 mu g ml(-1) (r = 0.9991) for CPZ. The limits of detection were 4.77 mu g ml(-1) and 0.71 mu g ml(-1) for MEB and CPZ, respectively. The limits of quantitation were 14.44 mu g ml(-1) and 2.14 mu g ml(-1) for MEB and CPZ, respectively. Degradation products of MEB, CPZ and impurities of CPZ did not interfere with the detection of MEB and CPZ. The proposed method can thus be considered as a stability indicating assay.