Determination of loratadine in human plasma by HPLC with fluorescence detector and study on its bioavailability

AimTo establish an HPLC-fluorescence method for determination of loratadine in human plasma and evaluate its relative bioavailability. MethodsAn Alltech-C₁₈ column and a mobile phase of acetonitrile-water-glacial acetic acid-triethylamine (90∶100∶6∶0.15) were used. The fluorescence detector was set at E_x 274 nm, E_m 450 nm. The flow rate was 1 mL·min^-1. ResultsThe calibration curve was linear over a concentration range of 0.2-30 μg·L^-1. The limit of quantification was 0.2 μg·L^-1. The average method recoveries varied from 96％ to 98％. The results showed AUC, t_max, C_max and t_1/2β between the testing tablets, testing capsules and reference tablets had no significant difference (P>0.05). Relative bioavailabilities were 107%±17% and 100%±14% respectively. ConclusionThe three formulations were bioequivalent.