HPLC determination of dexamethasone in human plasma

A sensitive high performance liquid chromatography (HPLC) method has been developed for the determination of dexamethasone in human plasma. After 1.5 mL of plasma was extracted with 4 mL of ethyl acetate containing 80 ng/mL of desoxymethasone, analysis of dexamethasone in plasma samples was carried out using a Sphereclone ODS2 column with UV detection for separation and quantification. A mixture of acetonitrile-10 mM phosphate buffer (pH 7.0) (32:68, v/v) was used as a mobile phase. The limit of quantitative (LOQ) analysis was 10 ng/mL. The accuracy of the assay was from 96.96% to 106.07%, while the intra- and inter-day coefficient of variation of the same concentration range was less than 15%, except LOQ (<20%). The signals were monitored by a UV detector at 240 bn with flow-rate of 1.0 mL/min. The method could be applied, with great success, to evaluate the bioavailability of dexamethasone in human subjects, with excellent selectivity and reproducibility and clinical study.