羟基喜树碱包衣纳米脂质体的制备及在小鼠体内组织分布的研究

 目的研究羟基喜树碱(HCPT)氯化壳聚糖(CS-HCl)包衣纳米脂质体(nanoliposomes)的制备方法,并考察其在小鼠体内的组织分布。方法采用薄膜分散法制备HCPT脂质体,用CS-HCl包衣后乳匀,得到CS-HCl包衣的HCPT纳米脂质体(平均粒径<100 nm)。除去游离HCPT后,测定其包封率(EE%)、平均粒径、粒径分布及Zeta电位。以5 mg·kg^-1羟基喜树碱的剂量小鼠尾静脉注射HCPT注射液、普通HCPT脂质体、HCPT纳米脂质体、包衣HCPT纳米脂质体,测定血浆及肝、脾组织中的血药浓度。结果包衣HCPT纳米脂质体的EE%为(61.2±1.20)%,平均粒径为(91.9±8.78)nm,Zeta电位为(55.1±1.04)mV(n=3)。包衣HCPT纳米脂质体在血液中AUC_0～48为HCPT纳米脂质体的1.3倍,为普通HCPT脂质体的4.7倍,为注射液的25.4倍。AUC_plasma/AUC_RES表明,包衣HCPT纳米脂质体为HCPT纳米脂质体的1.4倍,为普通脂质体的8.7倍,为注射液的3.4倍。结论该包衣HCPT纳米脂质体具有大小均匀,带有较大正电荷,能显著延长药物在血液循环中的时间,减少RES对脂质体的吞噬作用等特点。

Preparation of Chitosan Hydrochloride Coated Hydroxycamptothecin Nanoliposomes and Its Tissue Distribution in Mice

OBJECTIVE To investigate the preparation of hydroxycamptothecin(HCPT) nanoliposomes coated by chitosan hydrochloride(CS-HCl)and its tissue distribution in mice.METHODS HCPT nanoliposomes were prepared by the film dispersion method followed by chitosan hydrochloride coating.The liposomes were extruded to obtain the particle size below 100 nm.Liposomes contained HCPT and free HCPT were separated by a Sephadex-G50 chromatography.Ultraviolet spectrophotometry was used to determine the entrapment efficiency(EE %).The Zeta potential,average size and size distribution of the HCPT liposomes were also detected.HCPT injection,traditional HCPT liposomes,non-coated HCPT nanoliposomes and CS-HCl coated HCPT nanoliposomes were injected in tail vein at a dose of 5 mg·kg^-1 of HCPT,respectively.The HPLC-FLD was utilized for the determination of HCPT concentration in mice tissue,including plasma,liver and spleen.RESULTS The average EE% of the CS-HCl coated HCPT nanoliposomes was(61.2±1.20)%.The average size was(91.9±8.78)nm with the Zeta potential of(55.1±1.04)mV(n=3).The area under the curve(AUC_0～48)of plasma of CS-HCl coated HCPT nanoliposomes was 1.3-fold of that of the non-coated nanoliposomes while 4.7-fold of that of the traditional liposomes and 25.4-fold of that of the HCPT injection.The ratio of AUC_plasma/ AUC_RES of CS-HCl coated HCPT nanoliposomes was 1.4fold of that of the non-coated nanoliposomes while 8.7-fold of that of the traditional liposomes and 3.4-fold of that of the HCPT injection.CONCLUSION The results suggest that CS-HCl coated HCPT nanoliposomes have uniform sizes below nanometer degree and high positive Zeta potential.The AUC_0～48 of plasma is increased significantly and a longer circulation time is obtained after being coated by CS-HCl.