應用高效液相層析法同時測定兔子血漿中Betamethasone disodium phosphate及betamethasone之藥物濃度   全文下載

Simultaneous Determination of Plasma Betamethasone Disodium Phosphate and Betamethasone in Rabbit by High Performance Liquid Chromatography

Betamethasone disodium phosphate（BDP）為betamethasone（BTM）一個親水性前驅藥物，經靜脈注射入體內，在血中BDP 會快速地轉變成betamethasone。本研究建立一個高效液相層析分析法（HPLC），可同時分析血漿中的BDP 及BTM 樣品。結果顯示，校正曲線於50 ~ 6000 ng/mL 範圍內有良好的線性關係（BDP, R2 = 0.99999; BTM, R2 = 0.99997）及再現性。應用此分析方法於測定紐西蘭大白兔經靜脈注射BDP（0.4 mg/kg）後，BTM及BDP 的藥物動力學，所得結果，BDP 藥動學參數如下，半衰期：13.69 ± 2.70 min（Mean ± SEM, n = 6），清除率：3.96 ± 0.45 mL/min/kg，分佈體積：72.9 ± 9.67 mL/kg；BTM 藥動學參數，半衰期：228.58 ± 72.9 min ，清除率：3.50 ± 1.18 mL/min/kg ，分佈體積：327.57 ± 69.9 mL/kg 。所建立之BDP 和BTM 之HPLC 分析方法及藥物動力學參數或許可以應用於呼吸相關疾病之治療。"

Betamethasone disodium phosphate (BDP), a hydrophilic prodrug of betamethasone (BTM), was rapidly converted into betamethasone in blood following intravenous administration. In this study, we established an analytical method of high performance liquid chromatography (HPLC) to simultaneously determine BDP and its free base BTM in plasma samples. The calibration curves demonstrate good linearity (BDP, R2 = 0.99999; BTM, R2 = 0.99997) and reproducibility within a range from 50 ng/mL to 6000 ng/ mL. The analytical method was applied to determine the pharmacokinetics of BTM and BDP following intravenous bolus injection of BDP in New Zealand white rabbits (0.4 mg/kg). The determined pharmacokinetic parameters were listed as follows: for BDP, half-life: 13.69 ± 2.70 min (Mean ± SEM, n = 6), clearance: 3.96 ± 0.45 mL/min/kg and distribution volume: 72.9 ± 9.67 mL/kg; for BTM, half-life: 228.58 ± 72.9 min, clearance: 3.50 ± 1.18 mL/min/kg, and distribution volume: 327.57 ± 69.9 mL/kg. The established HPLC analytical method and related pharmacokinetic parameters of BDP and BTM might be potentially applied to use these drug administration in the treatment of respiratory relevant diseases.