Simultaneous estimation of tenofovir disoproxil, emtricitabine and efavirenz in tablet dosage form by RP-HPLC

A simple, precise, rapid and accurate reverse phase HPLC method in isocratic mode has been developed for the estimation of Tenofovir disoproxil, Emtricitabine and Efavirenz in tablet dosage form. A Hypersil BDS C18, 250x4.6 mm, 5 μm partical size, with mobile phase consisting of acetonitrile and 0.03 M KH2PO4 water (pH adjusted to 3.2 with orthophosphoric acid) in the ratio of 60:40 v/v was used. The flow rate was 0.8 ml/min and the effluents were monitored at 260 nm. The retention times were 3.105min for Emtricitabine, 3.860 for Tenofovir disoproxil and 10.549 min for Efavirenz. The detector response was linear for Tenofovir disoproxil, Emtricitabine and Efavirenz are in the range of 6-72 mcg/ ml, 4-48 mcg/ml and 12-144 mcg/ml respectively. The respective linear regression equation being Y=47439x-9882.3343 for Tenofovir disoproxil, Y=35167.413x+22780.1317 for Emtricitabine and Y=19958.961x+23536.8626 for Efavirenz. The limit of detection (LOD) for Tenofovir disoproxil, Emtricitabine and Efavirenz were found to be 0.03μg/ml, 0.04μg/ml and 0.12μg/ml respectively. The limit of quantification (LOQ) for Tenofovir disoproxil, Emtricitabine and Efavirenz were found to be 0.09μg/ml, 0.12μg/ml and 0.36μg/ml respectively. The percentage assay of Tenofovir disoproxil, Emtricitabine and Efavirenz was 98.78%, 98/57% and 98.28% respectively. The method was validated by determining its accuracy, precision and system suitability. The results of the study showed that the proposed RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of Tenofovir disoproxil, Emtricitabine and Efavirenz in bulk drug and in its pharmaceutical dosage form.