High-performance liquid chromatography determination of praziquantel in rat plasma; Application to pharmacokinetic studies

Abstract

A very simplistic, selective, sensitive, and reproducible procedure based on a reversed-phase high-performance liquid chromatography was used and developed for the determination of praziquantel in rat plasma. For the separation of praziquantel from the internal standard, diazepam on an Enable, C18 column (250±4.6 mm, 5 μm particle size), with the retention time of 6.4, 8.5 min, respectively. For praziquantel with UV detector at 225 nm. The mobile phase was a mixture of acetonitrile:water in a ratio of (60:40 v/v), running through the column at the flow rate of 1 ml/min. Sample preparation of 200 μl of plasma was done by a protein precipitation by using perchloric acid. Calibration curve was found to be linear with correlation coefficients (r2) is 0.9989 prepared in plasma at the concentrations of 5 to 1000 ng/ml. The precision of the above method was based on inter-day, and intra-day repeatability, and reproducibility (day-to-day variation) were found to be within the limit of 15%. Limit of quantification was accepted and found to be 5 ng/ml using 200 μl samples. The method appears to be robust and has been applied to a pharmacokinetic study of praziquantel in three groups of rats with a single oral dose of 40 mg/kg body weight.