新藤黄酸固体脂质纳米粒的制备与质量评价

目的制备新藤黄酸固体脂质纳米粒并进行质量考察。方法采用正交试验设计优化处方,以高温乳化-低温固化的方法制备新藤黄酸固体脂质纳米粒。并对其包封率、形态等进行研究。结果所制得的新藤黄酸固体脂质纳米粒外观形态圆整,粒度分布均匀,平均粒径为163.3 nm,包封率为(60.1±1.1)%。结论高温乳化-低温固化的方法适用于新藤黄酸-固体脂质纳米粒的制备。     

表面修饰唾液酸的唑来膦酸与多柔比星共载脂质体的制备

目的建立唑来膦酸与多柔比星包封率的测定方法,以包封率为指标优化唑来膦酸与多柔比星共载脂质体的处方及制备工艺,以期获得包封率高、稳定性好的制剂。方法将唑来膦酸配制成铵溶液作为水化介质,使用改良乙醇注入法制备唑来膦酸脂质体,在此基础上通过铵梯度法主动包载多柔比星以实现两种药物在脂质体中的共载。分别采用G-150葡聚糖凝胶微柱-高效液相色谱法与阳离子交换纤维微柱-紫外可见分光光度法测定唑来膦酸与多柔比星的包封率,通过对脂质体外水相中唑来膦酸的去除及对水化介质中阴离子浓度的考察,优化脂质体的处方与制备工艺。结果最优处方与工艺下制备的共载脂质体粒径约为110 nm,Zeta电位为-0.87 m V,其中唑来膦酸的包封率为6.5%,多柔比星的包封率大于90%。脂质体于4℃下避光放置60 d,粒径和包封率均无显著性变化,稳定性良好。结论唑来膦酸与多柔比星共载脂质体的包封率较高,稳定性较好。     

去氢骆驼蓬碱脂质体冻干剂粉的制备工艺优选

目的:制备含有不同冻干保护剂的N-三甲基壳聚糖(TMC)包衣去氢骆驼蓬碱脂质体(TMC-HM-LP)的冻干粉,并筛选其最佳制备工艺。方法:用"薄膜分散-pH梯度法"制备去氢骆驼蓬碱脂质体,并采用孵育包衣法、低温高速离心法和结合高效液相色谱(HPLC)定量方法测定其包衣脂质体的包封率;以其冻干粉的外观在冻干前和复溶后脂质体的粒径、包封率作为对比指标,优选出最佳的冻干工艺以及冻干保护剂的种类及比例。结果:以葡萄糖-乳糖-甘露醇(2:1:0.5)作为冻干保护剂,通过"分步预冻"的方法和-80℃冷冻干燥技术得到的TMC-HM-LP外观良好,冻干前后粒径和包封率变化较小。结论:采用冷冻干燥技术并结合冻干保护剂的优选,可显著提高包衣脂质体的稳定性。     

醋酸钙梯度法制备维A酸脂质体

目的:评价醋酸钙梯度法制备维A酸脂质体的可行性,并与薄膜法、逆相蒸发法进行质量比较。方法:采用薄膜法、逆相蒸发法和醋酸钙梯度法分别制备维A酸脂质体,用G-50葡聚糖凝胶柱分离,以紫外分光光度法和纳米激光粒度仪分别测定维A酸脂质体的包封率和粒径,以电子显微镜观察维A酸脂质体的形态。结果:以醋酸钙梯度法制备的维A酸脂质体包封率最高,达90.48%;其外观圆整均匀,平均粒径为35.8nm,4℃放置3mo质量稳定。结论:采用醋酸钙梯度法制备维A酸脂质体包封率较高,方法可行。     

酸敏脂质体的制备及其生物学活性

目的　对不同方法制备酸敏脂质体进行包封率测定及形态学观察 ,探讨酸敏脂质体包裹反义寡核苷酸的生物学效应。方法　测定四种不同方法制备包裹1 2 5I IL 8脂质体的包封率 ;在超高倍显微分析仪下观察形态结构。用包裹细胞磷脂酶A2 (cPLA2 )反义寡核苷酸的酸敏脂质体转染U937细胞 ,提取细胞RNA ,采用反转录 聚合酶链反应 (RT PCR) ;免疫印迹 (Westernblot)法检测cPLA2 蛋白的表达。结果　反相蒸发法与钙融合法联合制备的酸敏脂质体具有良好地包封率和形态结构 ,经酸敏脂质体包裹cPLA2 反义寡脱氧核苷酸可明显抑制cPLA2基因及蛋白的表达。结论　制备所得的酸敏脂质体可良好的发挥其生物学效应     

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。     

pH梯度法结合逆向蒸发法制备氟尿嘧啶脂质体

目的：以pH梯度法结合逆向蒸发法制备氟尿嘧啶脂质体,并评价其质量。方法：采用pH梯度法结合逆相蒸发制备氟尿嘧啶脂质体,以包封率为指标进行处方优化;用Sephadex G-50葡聚糖凝胶柱分离-高效液相色谱法测定氟尿嘧啶脂质体的包封率;以激光散射粒径分析仪测定脂质体的平均粒径及Zeta电位,透射电镜观测形态,并初步考察脂质体在室温和4℃冷藏条件下的稳定性。结果：制得的氟尿嘧啶脂质体外观形态圆整,平均粒径为282nm,Zeta电位为-25．9mV,平均包封率为75．39％,4℃冷藏条件下贮存脂质体的稳定性要明显优于室温贮存。结论：运用pH梯度法结合逆向蒸发法能制备包封率较高的氟尿嘧啶脂质体。     

全反式维甲酸前体脂质体的制备及体外评价

目的:制备维甲酸前体脂质体,并对其体外性质进行考察。方法:采用乙醇注入结合冷冻干燥法制备前体脂质体;微柱离心-高效液相色谱法测定脂质体的包封率;并进一步对其粒径、Zeta电位、血浆释放率及乙醇残留量进行测定。结果:所制备的前体脂质体包封率为95.2%,Zeta电位为-(28.4±17.5)mV,粒径为(170±29)nm,乙醇残留量为3.98%。结论:乙醇注入结合冷冻干燥法制备的维甲酸前体脂质体包封率高,粒径均匀,稳定性好。     

苦参碱脂质体的制备与包封率测定

目的 制备苦参碱脂质体并测定其包封率. 方法 采用硫酸铵梯度法制备苦参碱脂质体, 采用葡聚糖凝胶G-100分离苦参碱脂质体和游离苦参碱, 并用高效液相色谱法测定脂质体的包封率. 结果 苦参碱脂质体包封率为33.4%, 苦参碱在0.005～0.500 mg•mL-1范围内线性关系良好（r=0.999 8）. 结论 硫酸铵梯度法制备出包封率相对高的苦参碱脂质体, 高效液相色谱法测定脂质体的包封率简单快速, 方法准确, 重现性好.     

均匀设计法考察不同制备方法对氟尿嘧啶脂质体包封率的影响

目的考察不同制备方法对氟尿嘧啶脂质体包封率的影响,从而优选较好的制备方法.方法分别以薄膜分散法、逆向蒸发法、pH梯度法、以及硫酸铵梯度法制备氟尿嘧啶脂质体,用SephadexG 50葡聚糖凝胶柱分离 高效液相色谱法测定氟尿嘧啶脂质体的包封率,以包封率为指标运用均匀设计法优选制备方法和处方.结果主动载药法尤其是pH梯度法制得的氟尿嘧啶脂质体包封率明显优于被动载药法,包封率顺序为pH梯度法＞硫酸铵梯度法＞逆向蒸发法＞薄膜分散法.采用最优工艺制备氟尿嘧啶脂质体,平均包封率可达60.67%.结论制备方法对氟尿嘧啶脂质体包封率影响显著;pH梯度法能制得包封率较高的氟尿嘧啶脂质体.     

甘草次酸阳离子脂质体的制备及稳定性考察

目的:制备甘草次酸阳离子脂质体,并研究其稳定性。方法:用乙醇注入法制备甘草次酸阳离子脂质体。考察其粒径、包封率、过氧化值、在血浆中的稳定性和放样稳定性等性质。结果:所得脂质体的粒径小而均匀,呈球形和类球形,包封率为(91.6±1.2)%;离心加速试验结果显示脂质体的稳定性参数KE值较小,脂质体在血浆中释放缓慢,在4℃下放置6个月,其外观、包封率、粒径等各项指标无明显改变。结论:制得的甘草次酸脂质体包封率较高,稳定性良好。     

A novel method to prepare liposomes containing amikacin.

This work describes a novel method to prepare liposomal amikacin composed of soyabean lecithin and cholesterol; these were also prepared using two other methods (cast film method and proliposome method). Encapsulation efficiency was evaluated. Liposomes prepared by the new method, which combines the method of preparing proliposomes with freeze-drying, had the highest encapsulation efficiency. The influence of drug to lipid ratio on the encapsulation efficiency was investigated. The in vitro efflux of amikacin from liposomes with different lecithin: cholesterol ratios was also investigated.     

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。     

去氢骆驼蓬碱脂质体的制备和体外释放特性

目的：研究去氢骆驼蓬碱（harmine,HM）脂质体的制备工艺和体外释放特性。方法：运用薄膜分散-pH值梯度法制备HM．脂质体以及高速离心法分离脂质体与游离药物,并测定其包封率;借助综合评分法,评价其粒径、多分散系数、包封率、载药量指标;运用正交优化实验法考察磷脂-胆固醇与药-脂比、超声时间、外相pH值对脂质体的影响,述选最优工艺处方,评价脂质体与原料药的体外释放情况。结果：最优处方因素为磷脂-胆固醇比值为4：1,超声时间为300S,药-脂比值为1：5,外相pH值为6,8,即X13X23X32X43,经实验验证其粒径为（155.0±14．5）nm,多分散系数为（0．148±0．011）,包封率为（80．90±0．01）％,载药量为（11．16±0．01）％;其原料药0．5h累积释放百分比大于50％,不到2h已全部释放,而优化后的脂质体在1h内其累积释放百分比大于50％,4h后释放完成。结论：采用薄膜分散-pH值梯度法,以最优处方制得HM-脂质体,其粒径大小适中、形态均匀,包封率和载药量相对较高,体外释放显示具有较好的缓释特性。     

Development and Characterization of a Liposome Preparation by a pH-Gradient Method

Abstract— A pH gradient across liposome bilayers was established in order to load a model drug (orciprenaline sulphate) into liposome vesicles. This method of liposome loading resulted in yields as high as 80–85% encapsulation. An eight-step process was designed to scale-up the process and was evaluated. In this process a diafiltration technique was successfully used to remove the excess orciprenaline sulphate present in the external medium. Finally, drug-loaded liposomes were lyophilized using lactose as an internal and external liposomal cryoprotectant. Five-month stability data for the liposomes is reported. An HPLC technique was used to determine the drug concentration and a laser light-scattering technique was employed to determine the liposome vesicle size and polydispersity factor. Liposomes prepared by the pH-gradient method showed high encapsulation efficiency. Upon storage at 2–8°C the vesicle size increased and encapsulation efficiency decreased with time. These phenomena are attributed to gradual fusion of liposomes and loss of drug to the extra-liposomal media.     

Sustained tissue drug concentrations following inhalation of liposome-encapsulated fentanyl in rabbits

Liposomes are microscopic vesicles that can entrap drug molecules. Liposome-encapsulated fentanyl has been shown to provide sustained drug release following pulmonary administration. In this study, the effect of encapsulation efficiency (EE) of fentanyl within liposomes on the retention of fentanyl within the respiratory tract was examined. Liposomes with three different encapsulation efficiencies, 50% EE, 70% EE, and 90% EE, were manufactured with radiolabeled fentanyl and phospholipid dipalmitoyl phosphatidylcholine. The preparations were administered through an endotracheal tube to anesthetized rabbits, and the respiratory tracts were removed and analyzed for retention of fentanyl and DPPC at different time intervals. Increasing the encapsulation efficiency of fentanyl within liposomes is shown to prolong the retention of both fentanyl and DPPC within the respiratory tract. This suggests that the encapsulation efficiency can be manipulated to design a preparation to provide optimal therapeutic plasma fentanyl concentrations. The unencapsulated or “free” drug could act as a loading dose, and the slow, sustained release of fentanyl from the liposome depot in the lungs could act as a maintenance dose. Thus, this method of delivering a potent opioid, such as fentanyl, has the potential for clinical use in pain management.     

Development of a new topical system: Drug-in-cyclodextrin-in-deformable liposome

A new delivery system for cutaneous administration combining the advantages of cyclodextrin inclusion complexes and those of deformable liposomes was developed, leading to a new concept: drug-in-cyclodextrin-in-deformable liposomes. Deformable liposomes made of soybean phosphatidylcholine (PC) or dimyristoylphosphatidylcholine (DMPC) and sodium deoxycholate as edge activator were compared to classical non-deformable liposomes. Liposomes were prepared by the film evaporation method. Betamethasone, chosen as the model drug, was encapsulated in the aqueous cavity of liposomes by the use of cyclodextrins. Cyclodextrins allow an increase in the aqueous solubility of betamethasone and thus, the encapsulation efficiency in liposome vesicles. Liposome size, deformability and encapsulation efficiency were calculated. The best results were obtained with deformable liposomes made of PC in comparison with DMPC. The stability of PC vesicles was evaluated by measuring the leakage of encapsulated calcein on the one hand and the leakage of encapsulated betamethasone on the other hand. In vitro diffusion studies were carried out on Franz type diffusion cells through polycarbonate membranes. In comparison with non-deformable liposomes, these new vesicles showed improved encapsulation efficiency, good stability and higher in vitro diffusion percentages of encapsulated drug. They are therefore promising for future use in ex vivo and in vivo experiments.     

兰索拉唑脂质体的制备及其药剂学性质考察

目的:研究兰索拉唑阳离子脂质体的制备方法并考察其药剂学性质。方法:采用正交设计筛选处方,乙醇注入法制备兰索拉唑脂质体;超滤法测定其包封率;用透射电镜观察脂质体的外观形态,并用粒径分析仪和Zeta电位仪分别测定脂质体的粒径和Zeta电位;进一步考察脂质体的释放规律。结果:所得脂质体包封率约为(80±1.23)%;形态为粒径均匀的球形和类球形,粒径为(184±21)nm,Zeta电位为(36.1±5)mV;脂质体的体外释放符合一级方程;具有较好的稳定性。结论:优选得到的脂质体处方和制备工艺合理、稳定,其体外释放具有缓释特点。     

聚乙二醇单甲醚(2000)胆固醇琥珀酸酯包衣脂质体的研究

用聚乙二醇单甲醚 (2 0 0 0 )胆固醇琥珀酸酯 (PEGCHS)对脂质体进行包衣 ,以钙黄绿素(CF)为荧光探针 ,考察了不同PEGCHS加入量对脂质体包封率的影响 ,结果表明 ,随PEGCHS量的增加 ,包封率降低 .比较了包衣前后脂质体的体外、体内释放性 ,证明包衣后的脂质体 ,其体内半衰期大大延长 .     

兰索拉唑脂质体的制备及性质考察

目的研究兰索拉唑阳离子脂质体的制备方法并考察其体外释放行为及稳定性等。方法采用正交设计筛选处方;采用乙醇注入法制备兰索拉唑脂质体;采用超滤法测定其包封率;采用透射电镜观察脂质体的外观形态;采用粒径分析仪和Zeta电位仪分别测定脂质体的粒径和Zeta电位;采用透析法考察脂质体的释放规律。结果制得的脂质体包封率约为(80±1.23)%(n=3);脂质体的形态为粒径均匀的球形和类球形;粒径为(184±21)nm(n=3),Zeta电位为(36.1±5)mV(n=3);脂质体的体外释放符合一级方程,具有较好的稳定性。结论优选得到的脂质体处方和制备工艺合理,制剂性质稳定,其体外释放具有缓释特点。