a simple and sensitive hplc method for fluorescence quantitation of doxorubicin in micro-volume plasma: applications to pharmacokinetic studies in rats

a validated hplc method was developed to determine doxorubicin concentration in a small volume of rat plasma (60 µl) with convenient fluorescence detection. sample preparation includes a simple one-step liquid-liquid extraction using minimum amount of organic solvent, with extraction recoveries more than 95%. the analysis was accomplished using perfectsil c18 column maintained at 35 °c and a mobile phase consisted of acetonitrile and water (32:68, v/v; ph=2.6). the flow-rate was kept at 1 ml/min and column effluent was monitored with a fluorescence detector at an excitation and emission wavelength of 470 and 555 nm, respectively. the detection limit was 5 ng/ml. no analytical interference was observed from endogenous components in rat plasma. this method was feasibly applied to the pharmacokinetic study of 5 mg/kg of doxorubicin after intravenous administration to rats.