陈敏玲，张顺国，张健，吴皓(上海第二医科大学附属新华医院  上海200092)

摘  要  目的：建立豚鼠外耳淋巴液中磷酸地塞米松的含量测定方法。方法：采用浸满磷酸地塞米松溶液的明胶海绵颗粒置于圆窗龛内，采集给药1h后鼓阶外淋巴液。HPLC色谱条件为， ZORBAX  Eclipse XDB-C18色谱柱(4.6×250mm, 5μm)，流动相为7.56mmol/L硫酸铵-乙腈(70：30)，流速1.0ml min^-1，柱温20℃，紫外检测波长239nm。结果：磷酸地塞米松的线性范围为0.10～4.8mg•L^-1(γ=0.999 8)。最低检测限为6.25μg•L^-1，日内和日间RSD分别为1.7%和2.3%。给药1h后鼓阶外淋巴液中磷酸地塞米松的浓度为2.12mg•L^-1。结论：方法灵敏、准确，重现性好，可用于外淋巴液中磷酸地塞米松的测定。

关键词  磷酸地塞米松，外淋巴液，高效液相色谱法

Determination of the Content of Dexamethasone Sodium Phosphate in the Perilymph of Guinea Pig’s Tympanum after Administration by Gelfoam

Chen Minling, Zhang Shunguo， Zhang Jian，Wu Hao (Xinhua Hospital, Shanghai Second Medical University, Shanghai, 200092)

ABSTRACT Objective: To establish a method for determining the content of dexamethasone sodium phosphate in perilymph of guinea pig. Methods: Placing a granule gelfoam soaked with dexamethasone sodium phosphate in the niche of round window of guinea pig, perilymph of the scala tympani were sampled 1h after administration. HPLC conditions: ZORBAX Eclipse XDB-C18 column was taken as stationary phase (4.6×250mm, 5μm); 7.56mmol·L^-1 ammonium sulfate- acetonitrile (70:30) was taken as mobile phase with the flow rate of 1.0ml min^-1. The temperature of column was 20℃; the wavelength of detection was 239nm. Results: The calibration curve was linear within the concentration range of 0.10～ 4.8mg•L^-1(γ=0.999 8). The limit of detection was 6.25μg•L^-1, the RSD values of within-day and between days were 1.7% and 2.3%. The concentration of dexamethasone sodium phosphate in perilymph of the scala tympani was 2.12mg•L^-1 1h after administration. Conclusion: The method is simple, accurate, and reproducible. It can be used to determine the content of dexamethasone sodium phosphate in perilymph.

KEY WORDS Dexamethasone sodium phosphate, perilymph, HPLC