论文部分内容阅读
目的考察脂质体对7-乙基-10-羟基喜树碱(7-ethyl-10-hydroxycamptothecin,SN-38)活性形式的保护作用。方法建立测定SN-38活性形式的HPLC法,考察不同pH条件对SN-38活性与SN-38非活性形式相互转变动力学和平衡比例的影响;并研究了37℃的pH 7.4、8.0、9.0、10.0条件下脂质体对SN-38活性形式的保护作用。结果在pH<4.3的条件下,SN-38以其活性形式存在;在pH>9的条件下,SN-38主要以其非活性形式存在;在pH 6.5的条件下,SN-38活性和非活性形式之间相互转换最慢。包裹在脂质体内的SN-38在模拟生理条件下8 h活性形式质量分数仍大于98%。结论脂质体能够有效地保护SN-38α-羟基内酯环。
Objective To investigate the protective effect of liposomes on the active form of 7-ethyl-10-hydroxycamptothecin (SN-38). Methods The HPLC method for determining the active form of SN-38 was established to investigate the effect of different pH conditions on the kinetics and equilibrium ratio of SN-38 to SN-38 inactivation. The effects of pH at pH 7.4, 8.0 and 9.0 , 10.0 The protective effect of liposomes on the active form of SN-38. Results SN-38 was present in its active form at pH <4.3; SN-38 was predominantly in its inactive form at pH> 9; SN-38 activity at pH 6.5 was comparable to that of non-active The slowest conversion between active forms. The mass fraction of active form of SN-38 wrapped in liposomes at 8 h under simulated physiological conditions was still more than 98%. Conclusion Liposomes can effectively protect the SN-38α-hydroxylactone ring.