VALIDATED GRADIENT STABILITY-INDICATING UPLC METHOD FOR THE DETERMINATION OF LIDOCAINE AND ITS DEGRADATION IMPURITIES IN PHARMACEUTICAL DOSAGE FORM

Objective: Aim of the present work is to develop a stability indicating ultra performance liquid chromatography (UPLC) method to determine Lidocaine and its degradation impurities in pharmaceutical dosage forms. Method: Chromatographic separation was achieved by gradient elution on Agilent eclipse plus C18 (100x4.6) mm, and 1.8µm column with potassium dihydrogen phosphate buffer (pH 4.50) and acetonitrile within a short runtime of 14.0 min. The eluted compounds were monitored at wavelength of 230 nm using photodiode array (PDA) detector, the flow rate was 1.0 mL/min, and the column oven temperature was maintained at 40 ◦C. Result: The resolution of Lidocaine and six (potential, bi-products and degradation) impurities was greater than 2.0 for all pairs of components. The repeatability and intermediate precision, expressed by the RSD, were less than 1.0%. The accuracy and validity of the method were further ascertained by performing recovery studies. The specificity of the method was investigated under different stress conditions including hydrolytic, oxidative, photolytic and thermal as recommended by ICH guidelines. Relevant degradation was found to take place under oxidative condition. Conclusion: Method was Robustness against small modification in pH, column oven temperature, flow rate and percentage of the mobile phase composition was ascertained. All these results provide that the method has stability indicating properties being fit for its intended purpose; it may find application for the routine analysis of the related substances of Lidocaine formulations