This document describes the development and validation of an RP-HPLC method for the quantification of verapamil in drug substances and products. It involves selecting the optimal chromatographic conditions, such as the column, mobile phase, flow rate, and developing the method according to ICH guidelines. The method development steps include selecting the HPLC method and conditions, optimizing the selectivity and system parameters, and validating the method parameters like accuracy, precision, specificity, linearity and range. The goal is to develop a simple, accurate and precise RP-HPLC method for the analysis of verapamil that can be validated as per regulatory requirements.