Determination of Five Phosphodiesterase-5 Inhibitors in Multiple Honey-Based Consumer Products by Chromatographic Technique in Rat Plasma

Abstract

This study aimed to develop and verify a simple HPLC-based quantitative approach to simultaneously determine the phosphodiesterase-5 inhibitors (PDE5Is) sildenafil, vardenafil, udenafil, avanafil, and tadalafil in a tablet dosage form mixed with honey obtained form Jordanian market in rat plasma. PDE5Is block phosphodiesterase-5 (PDE-5). This blockage, in turn, triggers vasodilation by phosphorylating downstream effector molecules. Chromatographic separation was performed on a HypersilTM C18 column (150 mm × 4.6 mm, 5 µm, Thermo Fisher Inc., Waltham, MA, USA). An acetonitrile:10% Triethylamine solution (57:43) at pH 5.5 (adjusted with orthophosphoric acid), 20 µL injection volume, 1 mL/min flow rate, 25 °C temperature, and eluent monitoring at 250 nm was used to execute the current approach. Linearity was observed in the 9.6–14.4 µg/mL concentration ranges for sildenafil, udenafil, avanafil, and tadalafil, and 2.4–3.6 µg/mL for vardenafil. Each dosage form was recovered within acceptable limits at three distinct concentrations, and the assay selectivity indicated no interference from the inactive substances in the formulation. Sildenafil, vardenafil, udenafil, avanafil, and tadalafil had retention times of 3.5, 4.3, 6.2, 9.7, and 12.8 min, respectively, and tadalafil was 12.8 min. The present analytical method is comprehensive and universal for measuring the five drugs. Such an analytical method can be routinely used to detect the combination of these drugs.