Validated RP-HPLC method for quantification of felodipine in rabbit plasma: Application in a bioequivalence study

Abstract

The aim of present study was to develop a simple, rapid, selective, sensitive and robust reverse phase high performance liquid chromatographic method for quantification of felodipine in rabbit plasma at the wavelength of 360nm. Protein was precipitated from rabbit plasma sample by addition of acetonitrile as a vehicle. An isocratic elution of samples was performed on capcell pak C8 DD S5 column (4.6mm×250mm particle size 5μm) column with mobile phase consisting 5mM Phosphate Buffer (pH 4.8 adjusted with dilute ortho-phosphoric acid solution): acetonitrile (25:75:v/v) delivered at flow rate 1.0mLmin-1. A good linear response was achieved over the range of 0.25-20.00μgmL-1. LODs and LOQs for felodipine were found to be 0.055 and 0.201μgmL-1, respectively. The method was quantitatively evaluated in terms of linearity, precision, accuracy (recovery), selectivity robustness and stability study as per standard guidelines. The validated RP-HPLC method was successfully applied for the bioavailability studies of felodipine. The pharmacokinetic parameters were calculated for all the investigated drugs in rabbit after single-dose administrations of pure drug and formulation of felodipine. Finally, the obtained results for the application of the proposed RP-HPLC method proved its efficiency to be applied to the therapeutic drug monitoring (TDM) and bioequivalence (BE) studies. Thus, developed method is simple, convenient and suitable for the analysis of felodipine in bulk and pharmaceutical formulations.