DETERMINATION OF ERYTHROMYCIN IN HUMAN PLASMA AND WHOLE-BLOOD BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple, selective, sensitive, and rapid high-performance liquid chromatographic (HPLC) method is described for the quantitation of erythromycin (EM) in plasma and whole blood. The volume of plasma and whole blood and analytical time were only 0.2 ml and approximately 15 min. Analytical recovery of EM at concentrations of 0.2, 1.0 and 5.0 mug/ml after the complete extraction procedures with diethyl ether from alkalinized plasma and whole blood was > 75%. The coefficients of variation (CVs) for intra- and inter- day assay riabilities at 0.2, 1.0 and 5.0 mug/ml of EM were < 5.8% in plasma and < 6.3% in whole blood, respectively. The calibration curves for the respective analyte were linear (r = 0.994) over concentrations ranging from 0.1 to 5.0 mug/ml in plasma and whole blood. The lower detection limit for EM in plasma and whole blood was 0.1 mug/ml (CVs < 5.3%). This assay method is useful for the routine monitoring of EM in biological specimens.