Stability-Indicating RP-HPLC Method for the Simultaneous Estimation of Efavirenz, Tenofovir and Emtricitabine in Pharmaceutical Formulations

A simple, precise and rapid HPLC method has been developed for the simultaneous determination of Efavirenz, Tenofovir and Emtricitabine in pharmaceutical dosage form. The method was carried out using Zorbax C8 column (150 mm x 4.6 mm, 5 μm) and mobile phase comprised of mixture of dilute orthophosphoric acid solution pH 2.4±0.02 as buffer and acetonitrile in the ratio of 70:30 v/v and degassed under ultrasonication. The flow rate was 1.0 mL/min and the effluent was monitored at 252 nm. The retention times of Efavirenz, Tenofovir and Emtricitabine were 1.81 min, 2.80 min and 7.30 min respectively. The method was validated in terms of linearity, precision, accuracy, specificity, limit of detection, limit of quantitation and by performing recovery study. Linearity was in the range of 600.13 to 1800.39 μg/mL for Efavirenz, 300.54 to 900.44 μg/mL for Tenofovir and 200.46 to 601.38 μg/mL for Emtricitabine respectively. The percentage recoveries of all the three drugs were ranging from 98.2 to 101.9 for Efavirenz, 99.7 to 101.9 for Tenofovir and 98.7 to 101.6 for Emtricitabine respectively from the tablet formulation. The proposed method is suitable for the routine quality control analysis of simultaneous determination of Efavirenz, Tenofovir and Emtricitabine in bulk and pharmaceutical dosage form.