Capillary zone electrophoresis determination of loratadine in tablets

A capillary electrophoretic method was developed for the determination of loratadine in pharmaceutical formulations. Capillary zone electrophoresis (CZE) separation and UV absorbance photometric detection were carried out in a 160 mm capillary tube with a 300 μm internal diameter, hydrodynamically (membrane) closed. The influences of pH, carrier cation and counter ion on the migration parameters of loratadine were studied and the following conditions were selected: 24 mmol/l glycine as a carrier cation, 1.6 mmol/l citric acid and 84 mmol/l acetic acid as counter ions at pH 3.2, 100 μA and 25 °C. The proposed electrophoretic method was successfully validated. It was convenient for the sensitive, simple, rapid and highly reproducible assay of loratadine. The determination of loratadine in tablet forms was demonstrated as an application of the method. CZE analysis was completed within 6 min. The detection limit of loratadine was 1.96 μmol/l at a 240 nm detection wavelength and the relative standard deviation for its determination was 0.6% for migration time and 1.1% for peak area. CZE in a hydrodynamically closed separation system, used for the first time for the analysis of loratadine, should also be convenient for complex biological sample applications, as it is easily combinable on-line with the purification CE modes (e.g. ITP).