Simultaneous Determination of Emtricitabine and Tenofovir Disoproxil Fumerate in Tablet Dosage Form by UV-Spectrophotometry

Abstract

Three accurate, precise, sensitive and economical procedures for the simultaneous estimation of emtricitabine and tenofovir disoproxil fumerate in tablet dosage form have been developed. The methods employed were absorbance ratio method (I), absorbance correction method (II) and first order derivative spectroscopic method (III). The first method employs 262 nm as l₁ (isobestic point) and 281 nm as l₂ (l_max of emtricitabine) for formation of equations. The second method employs estimation of a drug concentration by selecting l_max where the absorbance of these drugs is maximum. But in one of the drug's lmax, the other drug has zero absorbance. So absorbance was corrected for interference. The l_max for emtricitabine and tenofovir disoproxil fumerate is 296 and 281 nm, respectively. The third method is based on first order derivative spectroscopic method. Wavelengths 298.5 nm and 226.5 nm were selected for the estimation of the emtricitabine and tenofovir disoproxil fumerate, respectively. Both the drugs obey Beer's law in the concentration range 4-24 μg/mL. The results of analysis have been validated statistically and by recovery studies.