西罗莫司脂质体的体外释放研究

Research on Drug Release in Vitro of Sirolimus Liposome

目的:研究西罗莫司脂质体的体外释放特性。方法:建立反相高效液相色谱法测定西罗莫司含量;采用反透析法,以500mL 20%乙醇为释放介质,考察24 h不同时间西罗莫司脂质体的体外累积释放率,利用药物释放模型方程拟合释放曲线。结果:西罗莫司检测浓度的线性范围为0.5～20 μg.mL^(-1)(r=0.999 8),平均回收率为99.42%,RSD=1.23%;脂质体前4 h的释药速率快,累积释放率为50%,之后释药相对缓慢,24 h的累积释放率为80%,释放曲线符合一级动力学方程。结论:西罗莫司脂质体具有一定缓释效应,其体外释放属于浓度依赖型渗透释药。

OBJECTIVE：To investigate release characteristics of sirolimus liposome in vitro.METHODS：The concentration of sirolimus was determined by RP-HPLC.In vitro release rate of sirolimus liposome within 24 h was investigated by the reverse dialysis method with 20% ethanol 500 mL as medium.Release curve of sirolimus was fitted with drug release model equation.RESULTS：The linear range of sirolimus were 0.5～20 μg.mL^-1（r=0.999 8）with an average recovery of 99.42%（RSD=1.23%）.At the first 4 hours of release,sirolimus liposome released rapidly with accumulative release rate of 50%.After that release rate of liposome was slowed down with accumulative rate of 80% in 24 h.The in vitro release curve conformed to the first order equation.CONCLUSION：Sirolimus liposome has delayed release capability,and in vitro drug release of sirolimus liposome is in concentration dependant manner.