用微透析法测定氢溴酸东莨菪碱凝胶经皮给药大鼠体内药动学研究

Study on pharmacokinetics of scopolamine hydrobromide gel transdermally administered in rats by microdialysis

目的:建立和验证大鼠皮下微透析样品中东莨菪碱浓度的HPLC-MS/MS法,初步研究氢溴酸东莨菪碱凝胶在大鼠经皮给药后的体内药动学。方法:采用Agilent Zorbax Extend C18色谱柱,柱温为40℃,以甲醇-2mmol/L甲酸铵(25∶75,甲酸调至pH 3.5)为流动相,流速0.3ml/min;质谱法采用正离子模式和多反应离子检测方式进行检测。结果:用于定量分析的离子对为m/z138.1～304.2,东莨菪碱的标准曲线线性范围为5.0～1 000ng/ml,日内和日间精密度及准确度均<15%。该药能迅速透皮,给药后150min即达峰浓度,后缓慢下降且维持在一较高浓度范围内,9h后在皮下的浓度迅速下降。结论:该方法灵敏度高、专属性强,可用于测定大鼠皮肤下微透析样品中东莨菪碱的含量。

Objective： To establish and validate the HPLC-MS/MS method for the determination of scopolamine concentra- tion in dermal microdialysis samples of rats, and study pharmacokineties of scopolamine hydrobromide gel transdermally admin- istered in rats. Methods： Scopolamine was separated with an Agilent Zorbax Extend C18 column. The mobile phase consisted of methanol-2 mmol/L ammonium formate（25 ： 75, the pH was adjusted to 3.5 by formic acid） at a flow rate of 0.3 ml/min and the column temperature was 40 ℃. The HPLC-MS/MS system was operated in the mode of multiple reaction monitoring with the electrospray ionization technique in positive mode. Results：Scopolamine was optimized at the transitions m/2 138.1 304.2. Calibration curve of scopolamine was linear within the range of 5.0-1 000 ng/ml. The inter day and intra day precision and accu- racy were all less than 15 %. Scopolamine could rapidly penetrate the skin and be absorbed. One hundred and fifty min after ad- ministration,the concentration of scopolamine reached peak, then dropped and maintained at a relatively high concentration range. The subcutaneous scopolamine concentration was decreased rapidly 9 h later. Conclusion： This method is sensitive and selective, and could be used to determine the concentration of scopolamine in the dermal microdialysis samples of the rats.