Rapid Analysis of Loratadine in Human Serum by High-Performance Liquid Chromatography with Fluorescence Detection

A simple and rapid high-performance liquid chromatographic method with fluorescence detection for analysis of loratadine (LOR) in small volumes of human serum has been developed and validated. After solid-phase extraction (SPE), with thioridazine hydrochloride as internal standard, chromatographic separation was performed on a C-18 analytical column with 70:30 (v/v) acetonitrile-water, adjusted to pH 2.7 with orthophosphoric acid as mobile phase at a flow-rate of 1 min mL(-1). The column was maintained at 28 degrees C. Fluorescence detection was performed at excitation and emission wavelengths of 265 of 454 nm, respectively. The method was validated for accuracy, precision, selectivity, linearity, recovery, and stability. Absolute recovery of LOR was >93.0%. The limits of detection (LOD) and quantification (LOQ) were 0.07 and 0.2 ng mL(-1), respectively. Linearity was confirmed in the range 0.-30 ng mL(-1) (correlation coefficient >0.9998). This HPLC method is selective, robust, and specific and would enable efficient analysis of large numbers of serum samples in support of pharmacokinetic, bioavailability, or bioequivalence studies after therapeutic doses of LOR.