Development and validation of new RP-HPLC method for the simultaneous estimation of metformin hydrochloride and repaglinide in pure and pharmaceutical formulations

Objective: A simple, accurate, precise, new RP-HPLC method was developed and validated for the determination of Metformin hydrochloride and Repaglinide in bulk and its pharmaceutical formulations. Method: The literature survey reveals that good analytical methods are not available for simultaneous estimation of drugs like Metformin hydrochloride and Repaglinide, which suffer from major disadvantage such as low sensitivity, lack of selectivity and simplicity. The existing physicochemical methods are inadequate to meet the requirements; hence a new RP-HPLC method has been developed for simultaneous estimation of Metformin hydrochloride and Repaglinide in bulk and its pharmaceutical formulations. A XBridge C18 (4.6 x 150mm, 3.5 μm, Make: Waters) or equivalent in an isocratic mode with mobile phase Potassium dihyrogen ortho phosphate (2.2 pH): Acetonitrile (35: 65%v/v) was used. The flow rate was 0.6ml/min and effluent was monitored at 240 nm. The retention time of Metformin hydrochloride and Repaglinide was 2.517 and 3.825 min. The linearity range was found to be 5–50μg/ml. The proposed method was validated statistically. Tablets of Metformin hydrochloride and Repaglinide [500.0mg and 2.0mg] was formulated in the lab scale for estimation by the developed method. Results: The method developed was approved for various parameters like accuracy, specificity, precision, range, linearity, robustness, LOD, LOQ and system suitability according to ICH guidelines. The results got were according the acceptance criteria. Conclusion: The sample recoveries in the formulation were in good agreement with their respective label claims and no interference of formulation excipients in the estimation. The technique could be easily and conveniently adopted for routine analysis of Zolpidem Tartrate in pure form and its dosage form and also for dissolution or similar studies.