s Simultaneous Estimation and Validation of Tenofovir Disoproxil Fumarate, Emtricitabine and Efavirenz by RP-HPLC Method in Combined tablet Dosage Form

Introduction: The purpose of this study is the development and validation of assay test for Tenofovir Disoproxil Fumarate (TDF), Emtricitabine (FTC) and Efavirenz (EFV) in combined tablet dosage form by Reverse Phase (RP) HPLC. Materials and Methods: The assay method by HPLC was found to be linear in the concentration range of 15-150 μg/mL, 10-100 μg/mL and 30-300 μg/mL for TDF, FTC, and EFV, respectively. Successful separation of combined drugs was achieved by isocratic elution on a Phenomenex® C8 column (250 mm x 4.6 mm, 5μm). The mobile phase was composed of buffer pH: 7.0 ± 0.05 potassium dihydrogen phosphate, acetonitrile and methanol (40:40:20 v/v) at the flow rate of 1 mL/min using UV detection at 262 nm, column oven temperature 25ºC, and injection volume 20 μL. Results: The analytical results were validated by recovery studies. All the parameters of validation were in the acceptance range. This developed method was successfully applied for simultaneous estimation the amount of TDF, FTC and EFV in the bulk and marketed dosage forms.