Development and Validation of a RP-HPLC Method to Quantify Amoxicillin, Tinidazole, Esomeprazole and Lansoprazole in a Mixture

Present investigation dealt with the developing of a reversed phase-high performance liquid chromatographic method for determination of amoxicillin, tinidazole, esomeprazole and lansoprazole in pure state and as a mixture. Chromatographic separation was performed isocratically on a LiChrospher (R) 100 RP-18 column. The flow rate was 1.0 ml/min and the detector was set at 280 nm. The method was developed at ambient temperature with a mobile phase, 40:60 v/v acetonitrile and phosphate buffer (0.001 M, pH 7.6). The selected conditions were applicable for separating amoxicillin, tinidazole, esomeprazole and lansoprazole with retention times 3.11, 5.37, 11.71 and 17.67 min, respectively. The method was validated for parameters including linearity, selectivity, precision and accuracy, limit of detection and limit of quantitation. Linear calibration curves were obtained in the concentration range of 250.0-2000.0, 125-1000.0, 5.0-40.0 and 7.5-60.0 mu g/ml for amoxicillin, tinidazole, esomeprazole and lansoprazole, respectively. The proposed method was found to be effective and could be used for quantification of these drugs in routine quality control practice.