Determination of mefloquine in biological fluids using high performance liquid chromatography

A simple, specific and sensitive High Performance Liquid Chromatography (HPLC) method for determination of whole blood of mefloquine has been developed. WR 184806 was used as internal standard, using a two step extraction procedure followed by revers phase HPLC. Acetonitrile and dichloromethane were used as extraction solvents. Octanesulphonic acid was used as an ionpairing reagent. Detection of extracted mefloquine and internal standard was achieved at 222 nm. Calibration curves for mefloquine in whole blood showed linearity with correlation coefficients of 0.9999. The limitation of detection using a 1 ml sample was 50 ng/ml. Recovery of mefloquine varied from 61% to 81%. Due to the very similar behavior of the internal standard during extraction, changes in recovery are of minor importance. Good accuracy and precision were obtained (intra-assay coefficient of variation ranged between 1.8% and 5%; inter-assay coefficient of variation were less than 10% at 100 ng/ml and less than 6% at 1,000 ng/ml). The assay employs a rapid and simple two-step extraction which requires a small sample volume. The low limit of detection of mefloquine and the short retention time make the method suitable for routine analysis of mefloquine.