Separation of Three Oxicams: Tenoxicam, Meloxicam and Lornoxicam by Ion Pair RP-HPLC

A rapid and stability indicating ion-pair reversed phase high performance liquid chromatographic method was developed for qualitative and quantitative estimation of three oxicam drugs: tenoxicam, meloxicam and lornoxicam. The method was validated according to ICH, FDA and USP guidelines with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity and system suitability. The method was developed by using an isocratic condition of mobile phase comprising buffer pH 6.5 [tetra butyl ammonium hydroxide (0.008M) and sodium 1-heptane sulfonate (0.003M)] and acetonitrile in a ratio of 65:35 v/v ratio at a flow rate of 1.5 mL/min over C-18 (ODS, 250 x 4.6 mm) column at ambient temperature. The method showed linear response with correlation coefficient (r2) value of 0.999. The recoveries for all drugs were found more than 99% which demonstrated the accuracy of this method. Intraday and inter-day precision studies of the new method were less than the maximum allowable limit (RSD%£ 2.0). Forced degradation studies were carried on to check its stability indicating property. All the drugs gave sharp peaks within 7min with excellent symmetry and high resolution. Therefore, a rapid, sensitive and stability indicating ion pair RP-HPLC  method was developed for simultaneous separation of tenoxicam, meloxicam and lornoxicam in their any combination or in bulk raw materials.