Development, Optimization and Validation of Analytical Procedures for The Simultaneous Determination of Selected Antiviral Drug Combinations

A novel, precise, and accurate methodology was developed for the quantification of Pibrentasvir (PBR) and Glecaprevir (GLE) in bulk dosage form using UV-Vis spectrophotometry, as well as for Lamivudine (LAM) and Tenofovir (TNF) in bulk drug formulation employing the RP-HPLC technique. The absorbance of GLE and PBR followed Beer's law within concentration ranges of 6.0 - 8.5 μg/ml and 2.0 - 4.5 μg/ml, respectively. For the simultaneous quantification of LAM and TNF in combination tablet formulations, chromatographic separation was achieved using a Phenomenex C18 column (250×4.6 mm, 5 µm) with a mobile phase consisting of phosphate buffer (pH 5) and acetonitrile (60:40 v/v) at a flow rate of 1 ml/min. The detection wavelength was set at 264 nm. The retention times for LAM and TNF were determined to be 4.4 minutes and 1.8 minutes, respectively. Multiple analytical performance metrics, such as linearity, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) were assessed and found to comply with International Council for Harmonization (ICH) guidelines (Q2A and Q2B). The established methods demonstrated good precision, with a relative standard deviation below 2% for both drug combinations.