Erdmann G R, Canafax D M, Giebink G S
Department of Pharmacy Practice, College of Pharmacy, University of Minnesota, Minneapolis 55455.
J Chromatogr. 1988 Dec 9;433:187-95. doi: 10.1016/s0378-4347(00)80597-6.
A reversed-phase high-performance liquid chromatographic procedure was developed to analyze 25-microliters volumes of chinchilla middle ear effusion and 50-microliters volumes of serum for trimethoprim and sulfamethoxazole. The small sample volumes were dictated by the chinchilla model of otitis media and our need to collect multiple samples over a 12-h drug dosing interval. The drugs were separated on a cyanopropylsilane column using acetonitrile-40 mM sodium phosphate, (16:84, v/v), pH 4.8. Trimethoprim and the internal standard were detected at 230 nm while sulfamethoxazole was detected at 250 nm. Middle ear effusion and serum samples were extracted with ethyl acetate-dichloromethane (25:75, v/v). The limit of quantitation was 0.5 micrograms/ml for sulfamethoxazole and 0.1 micrograms/ml for trimethoprim (coefficient of variation less than 20%), the limit of detection 0.25 and 0.05 micrograms/ml, respectively. Middle ear and serum samples of chinchilla with experimentally induced otitis media receiving 10 mg/kg trimethoprim and 50 mg/kg sulfamethoxazole intramuscularly were collected over a 12-h period and analyzed. All statistics that validate the analytic method are reported.
建立了一种反相高效液相色谱法，用于分析25微升的豚鼠中耳积液和50微升的血清中的甲氧苄啶和磺胺甲恶唑。由于中耳炎的豚鼠模型以及我们需要在12小时的给药间隔内采集多个样本，所以样本体积较小。药物在氰丙基硅烷柱上进行分离，流动相为乙腈-40 mM磷酸钠（16:84，v/v），pH 4.8。甲氧苄啶和内标在230 nm处检测，而磺胺甲恶唑在250 nm处检测。中耳积液和血清样本用乙酸乙酯-二氯甲烷（25:75，v/v）萃取。磺胺甲恶唑的定量限为0.5微克/毫升，甲氧苄啶的定量限为0.1微克/毫升（变异系数小于20%），检测限分别为0.25和0.05微克/毫升。在12小时内收集接受10毫克/千克甲氧苄啶和50毫克/千克磺胺甲恶唑肌肉注射的实验性中耳炎豚鼠的中耳和血清样本并进行分析。报告了所有验证该分析方法的统计数据。
