Hochhaus G, Hochhaus R, Werber G, Derendorf H, Möllmann H
College of Pharmacy, University of Florida, Gainesville 32610.
Biomed Chromatogr. 1992 Nov-Dec;6(6):283-6. doi: 10.1002/bmc.1130060607.
A combined high performance liquid chromatography/radioimmunoassay procedure is described for the simultaneous determination of dexamethasone (DEX) and its prodrug dexamethasone-21-sulphobenzoate sodium (DSS) in plasma. After precipitation of the plasma proteins by acetonitrile, the protein-free supernatant was injected onto a C18 reversed phase liquid chromatographic system and DSS- and DEX-containing fractions were collected. Hydrolysis of DSS by 0.01 N NaOH, followed by fractions extraction of both hydrolysed DSS and DEX fractions with ethyl acetate allowed the use of a dexamethasone-specific radioimmunoassay for the selective determination of both compounds. The method is accurate and reproducible (intraday variability for DSS and DEX < 6%, interday variability for DEX 14%), allowing quantification of DEX and DSS as low as 0.3 ng/mL and 0.7 ng/mL, respectively.
描述了一种高效液相色谱/放射免疫分析联用方法，用于同时测定血浆中的地塞米松（DEX）及其前药地塞米松-21-磺基苯甲酸钠（DSS）。用乙腈沉淀血浆蛋白后，将无蛋白上清液注入C18反相液相色谱系统，收集含DSS和DEX的馏分。用0.01N NaOH水解DSS，然后用乙酸乙酯对水解后的DSS和DEX馏分进行萃取，从而可以使用地塞米松特异性放射免疫分析来选择性测定这两种化合物。该方法准确且可重复（DSS和DEX的日内变异<6%，DEX的日间变异为14%），分别可定量低至0.3 ng/mL和0.7 ng/mL的DEX和DSS。
