Development and validation of a stability indicating HPLC method for the simultaneous analysis of lopinavir and ritonavir in fixed-dose combination tablets

Abstract

Abstract Objectives A simple, accurate, precise and rapid stability indicating HPLC method for simultaneous determination of Lopinavir and Ritonavir in combined dosage forms. Methods A validated stability indicating reversed phase high-performance liquid chromatographic method was developed for the quantitative determination of two antiviral drugs viz. lopinavir (LPV) and ritonavir (RTV) on Agilent TC C18 (2) 250 × 4.6 mm, 5 μ column using mobile phase composition of acetonitrile: 0.05 M phosphoric acid (55: 45, v/v) at a flow rate of 1.2 ml/min. Results Quantification was achieved with ultraviolet detection at 240 nm. The retention time obtained for ritonavir was at 4.35 min and for lopinavir was at 6.68 min. The result obtained with the detector response was found to be linear in the concentration range of 8–48 μg/ml for lopinavir and 2–12 μg/ml for ritonavir. This method has been validated and shown to be specific, sensitive, precise, linear, accurate, rugged, robust and fast. LPV and RTV were subjected to different accelerated stress conditions. The degradation products, were well resolved from the pure drug with significantly different retention time values. Conclusion It is concluded that this method can be applied for routine quality control of LPV and RTV in tablet dosage forms as well as in bulk drug. Hence the proposed method is highly sensitive, precise and accurate and it successfully applied for the reliable quantification of active pharmaceutical ingredient (API) content in the commercial formulations of lopinavir and ritonavir.