重酒石酸长春瑞滨脂质体包封率测定方法比较

目的制备重酒石酸长春瑞滨脂质体,比较葡聚糖凝胶微柱离心法和阳离子交换树脂离心法测定重酒石酸长春瑞滨脂质体包封率的差异。方法pH梯度法制备重酒石酸长春瑞滨脂质体,分别以葡聚糖凝胶Sephadex G-50和阳离子交换树脂装柱,离心分离脂质体和游离药物,采用HPLC法测定药物含量,计算包封率,并用SPSS软件进行t检验。结果两种方法测定不同载药量的脂质体包封率结果均无显著性差异(P>0.05)。结论葡聚糖凝胶微柱离心法和阳离子交换树脂离心法均可用来测定重酒石酸长春瑞滨脂质体包封率,优选阳离子交换树脂离心法。     

蔗糖八硫酸酯三乙胺梯度法制备重酒石酸长春瑞滨脂质体

 目的：制备重酒石酸长春瑞滨脂质体,并对制备工艺进行考察。方法：以蔗糖八硫酸酯三乙胺（triethylammonium sucrose octasulfate,TEA8SOS）梯度法制备重酒石酸长春瑞滨脂质体,以阳离子交换树脂分离脂质体与游离药物;并以紫外分光光度法和激光粒度仪分别测定重酒石酸长春瑞滨脂质体的包封率和粒径。结果：重酒石酸长春瑞滨脂质体包封率约为95%,粒径为129.5 nm。结论：以蔗糖八硫酸酯三乙胺梯度法制备的重酒石酸长春瑞滨脂质体包封率较高,方法可行。     

石杉碱甲脂质体制备及包封率的影响因素

目的建立石杉碱甲脂质体(huperzine A liposome,HUPA-L)的制备方法。方法采用pH梯度、硫酸铵[(NH4)2SO4]梯度、乙二胺四乙酸铵(NH4EDTA)梯度方法制备HUPA-L,以阳离子交换树脂分离脂质体和游离药物,HPLC法测定HUPA-L的包封率,并考察温度、孵化时间及药脂比对HUPA-L包封率的影响。体外释放实验研究HUPA-L的释放行为。结果硫酸铵梯度法制备的HU-PA-L包封率最高,包封率随着硫酸铵浓度和温度的升高而增加,随着药脂比的降低而增大,当药物与磷脂质量比小于1∶100时,HUPA-L包封率可达100.0%;HUPA-L体外释放呈现明显的缓释效果。结论硫酸铵梯度法是制备HUPA-L优选方法,硫酸铵的浓度、温度和药脂比是影响包封率的重要因素。     

主动载药法制备硫酸卷曲霉素脂质体及其质量评价

目的制备硫酸卷曲霉素脂质体,建立含量和包封率的测定方法,初步考察其体外释放规律。方法采用pH梯度法制备硫酸卷曲霉素脂质体,超滤法分离脂质体与游离药物,RP-HPLC测定脂质体的含量和包封率,透析法考察脂质体的体外释放行为。结果超滤法能很好地将脂质体与游离药物分离,测定硫酸卷曲霉素脂质体的含量为10.27mg/ml,包封率为47.8%,脂质体的体外释放规律符合一级动力学过程。结论pH梯度法适于制备硫酸卷曲霉素脂质体,超滤法可用于硫酸卷曲霉素脂质体包封率的测定,制备的脂质体具有一定的缓释效果。     

奥沙利铂脂质体的制备及体外释药研究

目的：制备一种包封率较高的奥沙利铂脂质体,并考察该脂质体的体外性质。方法采用多种方法制备奥沙利铂脂质体,通过单因素试验和正交试验最终确定脂质体处方。采用高效液相色谱法检测脂质体包封率, ZetaPlus 激光粒度分析仪测定脂质体粒径。同时,采用高效液相色谱法、原子吸收光谱法两种方法考察了该脂质体的体外释放情况。结果与薄膜分散法和 pH 梯度法相比,通过逆相蒸发法制备得到的了奥沙利铂脂质体包封率更高;在此基础上进行的处方筛选试验确定了最优处方工艺为药脂比1∶7.5,胆磷比1∶2,超声功率195 W,超声时间3 min;体外释放试验结果表明,通过高效液相色谱法和原子吸收光谱法测定的奥沙利铂脂质体24 h 的累计释放率分别为25.0%和33.6%。结论通过逆相蒸发法制备得到的奥沙利铂脂质体包封率高,且具有较高的稳定性和一定的缓释作用。     

pH梯度结合逆向蒸发法制备槐定碱纳米脂质体及体外释放度研究

目的:采用pH梯度结合逆向蒸发法制备槐定碱纳米脂质体,对影响包封率和粒径的因素进行考察,并对其体外释放进行评价。方法:以正交设计及单因素实验考察影响脂质体包封率及粒径的主要因素,同时对优化后的脂质体进行了质量评价及体外释放度研究。结果:磷脂的浓度为5 mg.mL-1,药脂比为1∶15,胆脂比为1∶4,内水相的pH值为2.0,均质压力为100 bar时,制备的脂质体包封率可达(90.30±0.63)%,脂质体外观圆整均匀,平均粒径为(117±6)nm。结论:pH梯度结合逆向蒸发法制备的槐定碱纳米脂质体包封率高,粒径均匀,稳定性好,具有一定的缓释作用。     

硫酸铵梯度法制备盐酸环丙沙星脂质体的影响因素

目的研究硫酸铵梯度法制备盐酸环丙沙星脂质体的影响因素。方法采用阳离子交换树脂-一阶导数分光光度法测定包封率 ,考察硫酸铵的作用及温度、药脂比对包封率的影响。结果在各种梯度法制备的盐酸环丙沙星脂质体中 ,硫酸铵梯度法得到的包封率可达 92 4 % ;盐酸环丙沙星脂质体的包封率随着硫酸铵浓度和温度的升高而增加 ,随着药脂比的增大而降低。结论硫酸铵梯度是盐酸环丙沙星脂质体包封率得以提高的主要原因 ,硫酸铵浓度、温度和药脂比是影响包封率的重要因素     

酒石酸长春氟宁脂质体的体内外评价

采用pH梯度法制备两种不同药脂比的酒石酸长春氟宁脂质体(vinflunine tartrate-loaded liposomes,VT-L)。运用激光粒度仪考察了脂质体的粒径分布和zeta电位;阳离子交换树脂-离心法测定了包封率;以酒石酸长春氟宁注射液(vinflunine tartrate injection,VT-I)为对照,比较了不同药脂比的VT-L对裸鼠体内肿瘤抑制和毒性的情况。结果显示,药脂比为1∶5和1∶10的VT-L平均粒径分别为124.6和128.3 nm,zeta电位分别为-25.3和-22.8 mV,包封率分别为94.46%和97.31%。两种药脂比的VT-L对人非小细胞肺癌A549裸鼠移植瘤的抗瘤效应明显优于VT-I,毒性低于VT-I。而两种药脂比的VT-L的抗瘤效应和毒性无显著差别。     

左旋多巴脂质体的制备及影响因素

目的将左旋多巴作成脂质体以备鼻黏膜给药,并考察其影响因素。方法用硫酸铵梯度法制备左旋多巴脂质体,采用电子显微镜和粒度测定仪考察脂质体的形态、粒径及分布;采用SephadexG50葡聚糖凝胶柱分离,高效液相法测定左旋多巴脂质体的包封率,考察硫酸铵浓度、温度以及药脂比对包封率的影响。结果左旋多巴脂质体的平均粒径为185nm,药物包封率为90.3%;包封率随着硫酸铵的浓度和温度的升高而增加,随着药脂比的增大而降低。结论采用硫酸铵梯度法制备左旋多巴脂质体包封率高、粒径小且均匀,方法简便易行;硫酸铵浓度、温度以及药脂比是影响包封率的主要因素。     

丹参素脂质体的制备及体外释放度研究

摘 要 目的： 制备丹参素脂质体并考察其体外释放度。方法: 采用逆相蒸发法制备丹参素脂质体,以包封率为指标,通过正交试验考察大豆卵磷脂浓度、大豆卵磷脂与丹参素药脂比和水相pH值。透射电镜观察所制备脂质体的形态和粒径,利用HPLC测定丹参素含量,透析法比较丹参素脂质体和游离丹参素的体外释放度。结果: 最佳制备工艺：磷脂浓度为40 mg·mL^-1,药脂比为1∶10,水相pH为6.6。制备的丹参素脂质体为圆整球形,平均粒径(174±36) nm,平均包封率38.9%。丹参素浓度范围在2.0～20.0 mg·L^-1的线性关系良好（r=0.998 4）,丹参素脂质体的体外释放度比游离丹参素慢,能达到24 h缓释。结论:采用逆相蒸发法制备的丹参素脂质体粒径大小均匀,具有一定的缓释效果。～     

柔红霉素长循环脂质体的药剂学性质及大鼠体内药代动力学研究

目的研究柔红霉素长循环脂质体的药剂学性质及大鼠体内药代动力学。方法考察柔红霉素长循环脂质体的形态和粒径分布、包封率和加速实验稳定性;建立脂质体中柔红霉素含量测定的可见分光光度法和HPLC方法;考察脂质体在Hepes缓冲液(pH 7.5)和大鼠血清中的体外释放行为。考察脂质体在大鼠体内的药代动力学行为。结果制备的柔红霉素长循环脂质体包封率高(>85%)、稳定性好,平均粒径为56.3 nm,体外释放慢;长循环脂质体的T_1/2α和AUC分别是注射剂的17.6和96倍。结论制备的长循环脂质体包封率较高,药剂学性质稳定,在大鼠体内的药代动力学参数优于注射剂,能达到长循环目的。     

A novel liposomal irinotecan formulation with significant anti-tumour activity: use of the divalent cation ionophore A23187 and copper-containing liposomes to improve drug retention.

We determined whether the method used to encapsulate irinotecan into 1,2-distearoyl-sn-glycero-phosphocholine/cholesterol (DSPC/Chol; 55:45 mol%) liposomes influenced: (i) irinotecan release rate and (ii) therapeutic efficacy. DSPC/Chol (55:45 mol%) liposomes were prepared with: (i) unbuffered CuSO4; (ii) buffered (pH 7.5) CuSO4; (iii) unbuffered MnSO4 and the ionophore A23187 (exchanges internal metal2+ with external 2H+ to establish and maintain a transmembrane pH gradient); and (iv) unbuffered CuSO4 and ionophore A23187. All formulations exhibited >98% irinotecan encapsulation (0.2 drug-to-lipid molar ratio; 10 min incubation at 50 degrees C). Following a single intravenous injection (100mg/kg irinotecan) into Balb/c mice, the unbuffered CuSO4 plus A23187 formulation mediated a half-life of irinotecan release of 44.4h; a >or=4-fold increase compared to the other liposome formulations. This surprising observation demonstrated that the CuSO4 plus A23187 formulation enhanced irinotecan retention compared to the MnSO4 plus A23187 formulation, indicating the importance of the divalent metal. A single dose of the CuSO4 plus A23187 formulation (50mg/kg irinotecan) mediated an 18-fold increase in median T-C (the difference in days for treated and control subcutaneous human LS 180 adenocarcinoma xenografts to increase their initial volume by 400%) when compared to a comparable dose of Camptosar. Improved irinotecan retention was associated with increased therapeutic activity.     

A targeted liposome delivery system for combretastatin A4: formulation optimization through drug loading and in vitro release studies

Efficient liposomal therapeutics require high drug loading and low leakage. The objective of this study is to develop a targeted liposome delivery system for combretastatin A4 (CA4), a novel antivascular agent, with high loading and stable drug encapsulation. Liposomes composed of hydrogenated soybean phosphatidylcholine (HSPC), cholesterol, and distearoyl phosphoethanolamine-PEG-2000 conjugate (DSPE-PEG) were prepared by the lipid film hydration and extrusion process. Cyclic arginine-glycine-aspartic acid (RGD) peptides with affinity for alphav beta3-integrins overexpressed on tumor vascular endothelial cells were coupled to the distal end of polyethylene glycol (PEG) on the liposomes sterically stabilized with PEG (non-targeted liposomes; LCLs). Effect of lipid concentration, drug-to-lipid ratio, cholesterol, and DSPE-PEG content in the formulation on CA4 loading and its release from the liposomes was studied. Total liposomal CA4 levels obtained increased with increasing lipid concentration in the formulation. As the drug-to-lipid ratio increased from 10:100 to 20:100, total drug in the liposome formulation increased from 1.05+/-0.11 mg/mL to 1.55+/-0.13 mg/mL, respectively. When the drug-to-lipid ratio was further raised to 40:100, the total drug in liposome formulation did not increase, but the amount of free drug increased significantly, thereby decreasing the percent of entrapped drug. Increasing cholesterol content in the formulation decreased drug loading. In vitro drug leakage from the liposomes increased with increase in drug-to-lipid ratio or DSPE-PEG content in the formulation; whereas increasing cholesterol content of the formulation up to 30 mol-percent, decreased CA4 leakage from the liposomes. Ligand coupling to the liposome surface increased drug leakage as a function of ligand density. Optimized liposome formulation with 100 mM lipid concentration, 20:100 drug-to-lipid ratio, 30 mol-percent cholesterol, 4 mol-percent DSPE-PEG, and 1 mol-percent DSPE-PEG-maleimide content yielded 1.77+/-0.14 mg/mL liposomal CA4 with 85.70+/-1.71% of this being entrapped in the liposomes. These liposomes, with measured size of 123.84+/-41.23 nm, released no significant amount of the encapsulated drug over 48 h at 37 degrees C.     

阿霉素的不同盐型对其脂质体体外药物泄漏和体内长循环的影响

目的探讨阿霉素不同盐型对脂质体体内外稳定性的影响。方法以薄膜分散-挤压法制备含有不同缓冲对的空白脂质体，用pH梯度和化学梯度法包载阿霉素，对其在脂质体内状态进行观察，测定了阿霉素脂质体理化性质；用透析法检测阿霉素脂质体在不同介质中的药物泄漏；用HPLC法研究不同盐型阿霉素脂质体在大鼠体内药代动力学行为。结果甘氨酸盐缓冲液、柠檬酸盐缓冲液和硫酸铵溶液作内水相制得的空白脂质体的平均粒径分别为(103±8)，(102±12)和(97±8) nm，zeta电位分别为(-21.3±0.5)，(-21.7±0.4)和(-20.9±0.7) mV，对阿霉素的包封率分别为47.8%，96.7%和98.6%。甘氨酸盐制得的脂质体体外泄漏最快，硫酸铵制得的脂质体泄漏最慢；甘氨酸盐缓冲液、柠檬酸盐缓冲液和硫酸铵溶液作内水相制得的阿霉素脂质体大鼠体内平均滞留时间分别为12.13，23.31和29.79 h。结论阿霉素在脂质体内水相中不同盐型影响其脂质体的体内外稳定性，以硫酸铵为内水相制得的阿霉素脂质体最稳定，其稳定次序与内水相中酸的强度有关，酸性越弱其脂质体稳定性越高。     

Formulation and characterisation of primaquine loaded liposomes prepared by a pH gradient using experimental design

The effect of different formulation factors (lipid type, cholesterol, charge, internal buffer capacity, drug-to-lipid incubation ratio) on the encapsulation efficiency and size of primaquine liposomes (SUV's) in response to a pH gradient was investigated by a fractional factorial screen ing design. Three of the factors (charge, internal buffer capacity, drug -to-lipid incubation ratio) were further studied in a Box--Behnken optimisation design. The lipid type was the most important parameter followed by the drug-to-lipid incubation ratio, buffer capacity, cholesterol and charge. Several of the interactions wer e important. In the optimisation design a robust region with high encapsulation efficiency (>95%) was obtained for DSPC: 33.33 mol% cholesterol-liposomes at high internal citrate concentration (200 mM) by maintaining the drug-to-lipid incubation ratio below 0.15:1 (mol:mol) and varying the charge incorporation between 2 and 10%. In order to achieve long-term stability and sterility, the liposomes were lyophilised followed by gamma irradiation. The pH gradient was maintained during this treatment with little chemical degradation of the substances. The final preparation consisted of three separate vials with lyophilised liposomes, solid state primaquine and hydration medium.     

曲马多缓释多囊泡脂质体的制备和释放度影响因素研究

目的 制备包封率高和缓释作用好的PGE修饰的曲马多缓释缓释多囊泡脂质体,并与逆相蒸发法制备的曲马多普通脂质体比较其体外释药性能.方法 用复乳法制备曲马多缓释多囊泡脂质体;非火焰原子吸收分光光度法测定曲马多含量;磷脂酶试剂法测定脂质体中磷脂的浓度;测定包封率和体外释药性.结果 曲马多缓释多囊泡脂质体平均粒径为31.3μm,跨距为1.0;曲马多包封率可高达80%以上;曲马多缓释缓释多囊泡脂质体的体外释药符合一级释药规律,释药时间为72h,比逆相蒸发法制备的曲马多普通脂质体延长16.95（由原来为释药时间37.7h延长8.4倍推出）倍;经差示热分析发现辅助膜稳定剂有明显的膜稳定作用.结论 曲马多缓释多囊泡脂质体包封率高,并具有良好的缓释作用.