A high performance liquid chromatographic (HPLC) method for the analysis of Lansoprazole and its associated impurities was examined with the aim of economic analysis, while maintaining good efficiency. The separation was carried out using a Chromatopak Peerless -C18 analytical column with a mobile phase composed of acetonitrile: buffer (500:500v/v) (buffer pH 10.0, adjusted with orthophosphoric acid) and was isocratically eluted at a flow rate of 1.0 mL min-1. Column oven temperature was 30ºC. A small sample volume of 20 µL was used for each sample run, being injected into the HPLC system. The chromatogram was monitored with UV detection at a wavelength of 254 nm and the total run time was 30 min. The method was validated according to ICH (international conference on harmonization) guidelines with respect to precision, accuracy, linearity, specificity, robustness and limits of detection and quantification. All parameters examined were found to be well within the stated guidelines.