LC-MS/MS法测定血浆及耳溢液中帕珠沙星:滴耳液药动学研究

LC-MS/MS analysis of pazufloxacin in human plasma and otorrhea:application to a pharmacokinetic study of ear drops

帕珠沙星滴耳液是一种治疗耳部炎症性感染的喹诺酮类局部使用制剂。本文建立了灵敏、快速的LC-MS/MS法测定人血浆及耳溢液中帕珠沙星浓度,用以评价帕珠沙星滴耳液的系统药动学及局部分布。人血浆样品及耳溢液样品均在蛋白沉淀法处理后通过HSS T3色谱柱(50 mm×2.1 mm,1.8μm)分离,采用含0.1%甲酸的1 mmol·L-1醋酸铵水溶液和甲醇为流动相,在0.55 mL·min-1的流速下进行梯度洗脱,以降低基质效应的影响。采用电喷雾电离源,在多反应监测模式(MRM)下测定,用于定量分析帕珠沙星和内标帕珠沙星-d4的离子对分别为m/z319.1→281.2和m/z 323.1→285.2。测定人血浆和耳溢液中帕珠沙星浓度的线性范围分别为0.0100~8.00 ng·mL-1和0.500~1000 ng·mg-1。两种基质样品的日内、日间精密度和准确度均在可接受范围内。本文临床试验经江苏省人民医院及南京市第一医院伦理委员会批准并在江苏省人民医院及南京市第一医院进行。经过验证后的方法成功应用于3名患有慢性化脓性中耳炎的受试者使用0.1%甲磺酸帕珠沙星滴耳液后的系统药动学及耳部药动学研究。

Pazufloxacin eardrops are a topical quinolone agent for the treatment of outer ear infection.The present study evaluated the pharmacokinetics and topical distribution of pazufloxacin eardrops by a sensitive LCMS/MS method for determining pazufloxacin in plasma and otorrhea.Plasma and otorrhea samples were extracted by acetonitrile-induced protein precipitation and were subjected to liquid chromatography-tandem mass spectrometric analysis with an electrospray ionization interface.The samples were separated on an HSS T3 column(50 mm×2.1 mm,1.8μm).To avoid the matrix effect,gradient elution was performed with the mobile phase consisting of methanol and 1 mmol·L-1 ammonium acetate aqueous solution(0.1%formic acid).The ion transitions for pazufloxacin and pazufloxacin-d4 were m/z 319.1→281.2 and m/z 323.1→285.2,respectively,under the multiple reaction monitoring(MRM)mode.The method was linear in the range of 0.0100-8.00 ng·mL-1 for pazufloxacin in plasma and 0.500-1000 ng·mg-1 in otorrhea.The intra-and inter-day accuracy and precision for pazufloxacin in plasma and in otorrhea met acceptable criteria.The clinical trial was approved by the Society of Ethics and conducted in Nanjing First Hospital and Jiangsu Province Hospital.The validated methods were used in a systemic and topical pharmacokinetic study of 0.1%pazufloxacin eardrops in 3 patients with chronic suppurative otitis media.