A novel validated RP-UPLC-DAD method for the simultaneous estimation of Emtricitabine, Tenofovir Disoproxil Fumarate, Cobicistat and Elvitegravir in bulk and tablet dosage form with forced degradation studies

Abstract

The aim of the present work was to develop and validate a rapid Reverse Phase Ultra Performance Liquid Chromatographic method for the simultaneous estimation of Emtricitabine, Tenofovir Disoproxil Fumarate, Cobicistat and Elvitegravir in its bulk and tablet dosage form with forced degradation studies. The separation was performed by ACQUITY UPLC BEH C18 (100 mm×2.1 mm, 1.7 m particle size) column, Waters ACQUITY UPLC system with PDA detector and mobile phase contained a mixture of 0.01M Ammonium acetate (pH adjusted to 7.5 with ammonium hydroxide) and Acetonitrile (45:55, v/v). The flow rate was set to 0.25 mL/min with responses measured at 268 nm. The retention time of Emtricitabine, Tenofovir Disoproxil Fumarate, Cobicistat and Elvitegravir was 0.904 min, 1.240 min, 2.615 min and 3.801 min with resolution of 4.05, 13.02 and 8.27 respectively. Linearity was established in the range of 20-100 µg/mL for Emtricitabine, 30-150 µg/mL for Tenofovir Disoproxil Fumarate, 15-75 µg/mL for Cobicistat and 15-75 µg/mL for Elvitegravir with correlation coefficients (r 2 =0.999). The percentage recoveries were between 99.55-99.96%, 100.04-100.07%, 99.86-100.09% and 99.95-100.19% for Emtricitabine, Tenofovir Disoproxil Fumarate, Cobicistat and Elvitegravir respectively. Validation parameters were evaluated according to the International Conference on Harmonization (ICH) Q2 R1 guidelines. The forced degradation studies were performed by using HCl, NaOH, H2O2, thermal and UV radiation. Emtricitabine are more sensitive towards alkaline hydrolysis degradation condition, Tenofovir Disoproxil Fumarate is more sensitive towards oxidative degradation condition, Cobicistat are more sensitive towards alkaline hydrolysis degradation condition and Elvitegravir are more sensitive towards acidic hydrolysis degradation condition. The developed method was successfully applied for the quantification and hyphenated instrumental analysis.