A Validated Stability Indicating Rp-hplc Method for Simultaneous Determination of Lopinavir and Ritonavir in Bulk and Tablet Dosage Form

A rapid and precise reverse phase high performance liquid chromatographic method has been developed for the validated of Lopinavir and Ritonavir in its pure form as well as in tablet dosage form. Chromatography was carried out on a Kromasil C18 (4.6 x 250mm, 5μm) column using a mixture of TEA buffer (pH 4.0), Methanol in proportion 65:35 v/v as the mobile phase at a flow rate of 1.0ml/min, the detection was carried out at 227nm. The retention time of the Lopinavir and Ritonavir were found to be 2.079, 4.045 min respectively. The method produce linear responses in the concentration range of 5-35μg/ml for both Lopinavir and Ritonavir. The method precision for the determination of assay was below 2.0% RSD. The method is useful in the quality control of bulk and pharmaceutical formulations. The optimized method was validated and proved to be suitable for the quality control of the mentioned drugs in their different pharmaceutical dosage forms, according to ICH guidelines. The developed method was found to be fairly precise, rapid and economical for simultaneous estimation of Lopinavir and Ritonavir when compared with the reported method.