New and validated RP-HPLC Method for Quantification of Safinamide Mesylate in Presence of Its Basic Degradate, Levodopa and Ondansetron: Application to Human Plasma

A simple, precise, rapid and accurate reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for analysis of safinamide mesylate (SAF) in presence of its basic degradate, and co-administered drugs levodopa and ondansetron. The mobile phase consisted of acetonitrile and 20 mM potassium dihyrogen orthophosphate buffer having pH = 5 (40: 60 v/v). Quantification was achieved with ultraviolet detector at 226 nm. The linear range was 0.5-10 μg/mL with mean recovery ± SD of 99.72 ± 1.59. The peak purity of SAF in pharmaceutical preparation spiked with its degradate and co-administered drugs revealed symmetry factor (999.8) within the calculated threshold (>998.1). The suggested method was validated in compliance with the International Conference on Harmonization (ICH) guidelines and statistically compared with the manufacturer HPLC method with no significant difference in terms of accuracy and precision. The assay method was successfully used to estimate SAF in tablets with good percentage recoveries. The high sensitivity (lower than Cmax of the drug 0.65 μg/mL) of the proposed HPLC method enabled the determination of SAF in presence of its basic degradate and co-administered drug, ondansetron in human plasma with acceptable accuracy. The suggested HPLC method could be used in Quality Control (QC) lab for analysis of the studied drug in pharmaceutical preparation.