STABILITY INDICATING METHOD DEVELOPMENT AND VALIDATION OF LACOSAMIDE AND ITS RELATED SUBSTANCES IN PHARMACEUTICAL FORMULATION BY RP-HPLC

A simple, sensitive, and precise high performance liquid chromatographic method for the determination  of  related substances of  Lacosamide in pharmaceutical formulation  has  been  developed,  validated and used  for the determination of related substances in commercial pharmaceutical products. The Impurities were well separated on a Inertsustain HP C18 (100mm X 4.6mm, 3µm) by the gradient program using method pH 2.00 KH₂PO₄ buffer: Acetonitrile (98:2 v/v) as mobile phase-A and Acetonitrile: water (60:40 v/v) as a mobile phase-B which gives good resolution and good peak shapes for Lacosamide and their related substances at a flow rate of 1.5 mL/min with detection wavelength at 210 nm. Calibration curves were found linear with correlation coefficient of 0.999 with a linearity range LOQ -200%. The developed method was validated for specificity, accuracy, precision, recovery, linearity, robustness, ruggedness and system suitability. The percentage of recovery of Lacosamide was found to be 96.92%, at 100% level their related substances was found to be within acceptance range. The method was found to be stable with no interference with degradation products.