RP-HPLC method development for simultaneous estimation of empagliflozin, pioglitazone, and metformin in bulk and tablet dosage forms

Abstract

Empagliflozin, pioglitazone, and metformin are antidiabetic drugs used alone or together to treat diabetes. An economical, simple, precise, selective, and stability-indicating RP-HPLC method has been established and validated to evaluate these drugs in bulk and tablet dosage forms. ICH guidelines were followed, where the separation of the drugs using a mobile phase prepared by mixing orthophosphoric acid buffer and acetonitrile (30 : 70 v/v) adjusted to pH 2.7 was followed. An ACE C18 -(250 mm x 4.6 mm), 5 m column at a flow rate of 0.5 mL/min at 25C, and detection monitored at 230 nm were used. The R2 was not < 0.9998 in the range of 20-250 ppm. For stability study, drugs were studied using variant stress conditions such as base, acid, neutral, oxidation, and thermal degradation. Results were validated for the limit of detection, the limit of quantification, precision, accuracy, and linearity. The method also proved robust concerning variations in pH of the mobile phase, detector-wavelength, temperature, and mobile phase composition. The retention time of empagliflozin, metformin, and pioglitazone was 3.2 min, 2 min, and 2.6 min, respectively, with a runtime of 7 min. Detector linearity was obtained at 10-100 ppm, with the correlation coefficient for empagliflozin, pioglitazone, and metformin being 0.9994, 0.9993, and 0.9998, respectively. The low relative standard deviation, i.e., <2%, validated results, and high recovery% affirm the suitability of this method for being employed for the routine analysis of bulk and tablets containing these drugs in pharmaceutical formulation.