A simple and sensitive LC-MS/MS method for quantification of Bepridil in rat plasma and its application to pharmacokinetic studies

Abstract Bepridilis potent inhibitor of Na + , K + and Ca + channel in cardiomyocytes. It has demonstrated strong antianginal effect with type I antiarrhythmic and with minimum antihypertensive therapeutic effect. Till date, a specific LC–MS/MS method to quantify Bepridilconcentrations in biological matrix have not been reported yet. In current study, a highly sensitive, specific and simple LC–MS/MS method for quantification of antianginal drug Bepridilin rat plasma is presented. The LC–MS/MS method was validated in terms of selectivity, specificity, sensitivity, accuracy and precision, matrix effect, extraction recovery and stability as per USFDA’s bioanalytical method validation guideline. The validated assay was applied for quantification of Bepridilfrom pharmacokinetic study in rats following oral and intravenous administration. The lower limit of quantification (LLOQ) of Bepridilwas 1 ng/mL. The calibration curveranges from 1 ng/mL to 1000 ng/mL with desirable linearity and r 2 > 0.99. The method exhibited 10-fold dilution integrity. The intra-day and inter-day accuracy were within 101.32–96.80% and 102.87–95.35% with coefficient of variation 10.11–2.89% and 10.45–3.97% respectively. No significant interference observed by endogenous peak at the retention time of Bepridiland IS. The assay was free from any matrix effect, precise recovery across the calibration curverange and samples were stable under all experimental conditions. The validated assay was successfully applied to analyze plasma samples of pharmacokinetic study in rat to determine concentrations of Bepridil. In summary, a novel method for analyzing Bepridilin rat plasma has been successfully validated and is now being utilized for quantification of Bepridilfrom pre-clinical studies.