Lovdahl M J, Reher K E, Russlie H Q, Canafax D M
College of Pharmacy, University of Minnesota, Minneapolis 55455.
J Chromatogr B Biomed Appl. 1994 Mar 4;653(2):227-32. doi: 10.1016/0378-4347(93)e0420-u.
A high-performance liquid chromatographic method has been developed to determine cefpodoxime levels in chinchilla plasma and middle ear fluid (MEF) to be used in studying otitis media. Cefpodoxime and the internal standard, cefuroxime, were separated on an ODS column (250 x 2.1 mm I.D., 5 microns Hypersil), using a mobile phase of 25 mM acetate buffer (pH 4.3)/15 mM triethylamine-acetonitrile (92.5:7.5, v/v). Following elution of cefpodoxime and the internal standard, at 3.5 and 5.9 min respectively, the acetonitrile concentration was increased to 1:1 (v/v) in a step function to elute endogenous compounds retained on the column. Sample preparation involved protein precipitation with acetonitrile. This fast, efficient protein precipitation procedure together with UV detection allows a quantitation limit of 50 ng/ml with a 50-microliters sample size. Recoveries (mean +/- S.D., n = 3) at 0.1 microgram/ml in MEF were 90.3 +/- 2.9% and 88.6 +/- 1.2% for cefpodoxime and cefuroxime respectively. Recoveries (mean +/- S.D., n = 3) at 0.1 microgram/ml in plasma were 72.1 +/- 7.3% and 81.1 +/- 1.1% for cefpodoxime and cefuroxime respectively. The method was evaluated with biological samples taken from chinchillas with middle ear infections after administering cefpodoxime proxetil.
已开发出一种高效液相色谱法，用于测定用于研究中耳炎的龙猫血浆和中耳液（MEF）中的头孢泊肟水平。头孢泊肟和内标头孢呋辛在ODS柱（内径250×2.1mm，5μm Hypersil）上分离，流动相为25mM醋酸盐缓冲液（pH 4.3）/15mM三乙胺 - 乙腈（92.5:7.5，v/v）。头孢泊肟和内标分别在3.5分钟和5.9分钟洗脱后，乙腈浓度以阶跃函数增加至1:1（v/v），以洗脱保留在柱上的内源性化合物。样品制备包括用乙腈进行蛋白沉淀。这种快速、高效的蛋白沉淀程序与紫外检测相结合，使得50微升样品量的定量限为50纳克/毫升。在MEF中0.1微克/毫升时的回收率（平均值±标准差，n = 3），头孢泊肟和头孢呋辛分别为90.3±2.9%和88.6±1.2%。在血浆中0.1微克/毫升时的回收率（平均值±标准差，n = 3），头孢泊肟和头孢呋辛分别为72.1±7.3%和81.1±1.1%。该方法用给予头孢泊肟酯后取自患有中耳感染的龙猫的生物样品进行了评估。
