Development and validation of a stability indicating capillary electrophoresis method for the determination of metformin hydrochloride in tablets

A simple and a stability indicating capillary electrophoresis method was developed and validated for the analysis of metformin hydrochloride in tablet formulation. The method employed 40 mM citrate buffer at pH 6.7 as a background electrolyte with an applied voltage of 15 kV (positive polarity). The capillary used was of 68.5 cm length (60 cm to detector) and the detection wavelength was 230 nm. The method was validated in accordance with the ICH requirements, which involved accuracy, precision, linearity, selectivity and both limit of detection and limit of quantitation. The current method was linear over the concentration range of 0.2–2.0 mg/ml of metformin hydrochloride. The method was precise as reflected by inter-day and intra-day relative standard deviation (RSD) of less than 2%. The limit of detection and limit of quantitation were 2.0 μg/ml and 8.0 μg/ml, respectively. The stability indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using photodiode array detection.