Simultaneous Quantification of Efavirenz and Lamivudine in Tablet Dosage Form by Liquid Chromatography

A simple, rapid and accurate reverse phase-high performance liquid chromatographic method for the simultaneous determination of lamivudine and efavirenz in tablet dosage form is developed and validated. The chromatographic analysis was performed on a Thermo BDS hypersil C 18 column (250×4.6 mm, 5 µm) in isocratic mode, the mobile phase consisted of methanol, acetonitrile and 0.05 M phosphate buffer (adjusted to pH 4.5 with ortho-phosphoric acid) at a ratio of 60:20:20 v/v/v, and a flow rate of 1.0 mL/min. The eluents were monitored at 254 nm. The retention time of lamivudine and efavirenz were found to be 2.50 min and 4.25 min, respectively. The linear ranges were found to be 10-60 2 2 µg/mL (r =0.9992) for lamivudine and 10-60 µg/mL (r =0.999) for efavirenz. The proposed method is also found to be accurate, precise and robust. The method could be applied to routine quality control of pharmaceutical formulations containing lamivudine and efavirenz.