DOE-OPTIMIZED RP-HPLC METHOD FOR SIMULTANEOUS QUANTIFICATION OF EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE IN TABLETS

Abstract

A robust and efficient RP-HPLC method was developed and validated for the simultaneous quantification of Emtricitabine and Tenofovir Disoproxil Fumarate in both bulk drug and tablet dosage forms. Employing a Design of Experiments (DOE) approach, the mobile phase was optimized using methanol, pH, and flow rate as independent variables. The method achieved retention times of 3.25 min for Tenofovir Disoproxil Fumarate and 4.16 min for Emtricitabine, using a gradient mobile phase composed of 20 mM phosphate buffer and acetonitrile in methanol at a 50:50 v/v ratio (pH 3.0) and a flow rate of 0.7 ml/min, on a Targetsil C18 – 5µm column at room temperature. Detection was performed at an isosbestic wavelength of 238 nm over 10 minutes. Linear responses were observed over concentration ranges of 10-30 µg/ml for Tenofovir and 5-25 µg/ml for Emtricitabine. The limits of detection (LOD) and quantitation (LOQ) for the drugs were 1, 0.5, and 3 µg/ml and 1.5 µg/ml, respectively. The method met the ICH guideline criteria for linearity, accuracy, precision, specificity, and robustness, demonstrating its suitability for the simultaneous estimation of these drugs in combined dosage forms. This validated method addresses the critical need for effective analytical techniques in pharmaceutical quality control, particularly for HIV medications.