Preparation and evaluation of paclitaxel-containing liposomes

Paclitaxel, an antitumoral drug, is poorly soluble in aqueous media. Therefore, in a commercialised formulation (Taxol), paclitaxel (30 mg active compound) is dissolved in polyethoxylated castor oil (Cremophor EL) and ethanol. After dilution of Taxol in aqueous media paclitaxel tends to precipitate. Several side effects, attributed to the surfactant Cremophor EL, occur, e.g. bronchospasm, hypotension, neuro- and nephrotoxicity, and anaphylactic reactions. To eliminate these side effects, the solubility of paclitaxel was enhanced using liposomes instead of Cremophor EL. The amount of entrapped paclitaxel in crystal-free liposomes was 0.5 mg/ml liposome suspension, i.e. almost 85 times the native solubility. Thus, 30 mg paclitaxel had to be dissolved in 60 ml liposome suspension, of either multi-lamellar vesicles (MLV's) or of small unilamellar vesicles (SUV's) with 5% sucrose as cryoprotector. No precipitation was observed after dilution of the MLV-formulation with (physiological) water or with 5% aqueous dextrose solution, which proves their suitability for administration with perfusions. The chemical stability of paclitaxel in the prepared MLV's stored at 4 degrees C was demonstrated during a period of 5 months. The chemical degradation to conjugated dienes and hydroperoxides, two oxidative degradation products of EPC, was negligible (less than 1%).     

川芎嗪脂质体的制备和质量评价

目的：制备川芎嗪脂质体，考察其理化性质。方法：以磷脂-胆固醇（2．5：1．5）为包封膜材，采用注入乳匀法制备川芎嗪脂质体，观察脂质体形态，测定其粒径，采用HPLC法测定川芎嗪含量，并考察其包封率、载药量和稳定性。结果：川芎嗪脂质体平均粒径为200nm，包封率和载药量分别为（39．5±0．66）％和（0．719±0．011）％。4℃保存30d稳定。结论：以本方法制备的川芎嗪脂质体质量符合《中华人民共和国药典》的要求。     

Preparation and evaluation of doxorubicin-luminespib co-loaded multivesicular liposomes

A combinational therapeutic system that simultaneously administrates various pathways is preferred for anti-cancer treatment. In the present study, we successfully constructed a co-delivery system, multivesicular liposomes (MVLs) co-encapsulating doxorubicin (DOX) and luminespib (AUY922). A simple and accurate dual-wavelength spectrophotometric method was established for the determination of DOX and AUY922 in liposomal formulation. MVL-loading drugs were prepared by a multi-emulsion solvent evaporation method, which exhibited excellent physicochemical properties, such as particle size of 3–8 μm and high entrapment efficiency above 95% for DOX and 73% for AUY922. The synergetic cytotoxic effect for these two drugs was evaluated in MDA-MB-231 cells. The in vitro antitumor studies demonstrated the superior anti-proliferation activity of DOX and AUY922 with a combination index of 0.43, indicating a great synergistic effect. The experimental data suggested that combinational use of DOX and AUY922 within liposomes could be an effective way to develop efficient treatments of cancers.     

盐酸利多卡因多囊脂质体的制备和质量评价

目的:制备具有缓释特性的盐酸利多卡因多囊脂质体,考察其理化性质。方法:以卵磷脂和胆固醇为膜材,采用复乳法制备盐酸利多卡因多囊脂质体,用透射电镜观察其外观形态,用激光粒度分析仪测定粒径,检测包封率和体外释药特性。结果:盐酸利多卡因多囊脂质体的外观形态圆整、规则,粒径分布在300～700nm及1～6μm两区域,包封率为(27.10±0.66)%。多囊脂质体在pH 7.4的磷酸盐缓冲液中,24h的累积释药百分率为(92.7±3.6)%。结论:盐酸利多卡因多囊脂质体具有一定的缓释特性。     

硫酸阿米卡星多囊脂质体的制备及评价

目的 制备硫酸阿米卡星多囊脂质体(amikacin sulfate multivesicular liposomes, AMK-MVLs),对其进行质量评 价,并考察了其体外抗菌活性。方法 采用复乳法制备AMK-MVLs混悬液Ⅰ,Box-Behnken效应面法优化筛选最佳处方,采 用生理盐水洗涤后调整药物浓度得AMK-MVLs混悬液。采用光学显微镜、激光粒度仪、差示扫描量热(differential scanning calorimeter,DSC)考察制剂的理化性质,采用透析法考察其体外释放规律,通过微量稀释法初步考察其体外抗菌活性。结 果 优化得到AMK-MVLs混悬液Ⅰ的最佳处方为：大豆磷脂与胆固醇质量比为1.91:1,三油酸甘油酯用量为1.02%,PVA用量为 0.62%。AMK-MVLs呈堆叠有无数囊泡的非同心球状,AMK-MVLs混悬液包封率(87.12±1.55)%,平均粒径为11.93 μm。DSC 结果表明,AMK以无定型状态存在于脂质体内。体外释放结果显示AMK-MVLs混悬液在72 h时释药约80%。体外溶血实验表 明,AMK-MVLs脂质体粒子浓度低于400 μg/mL时无溶血风险。体外抗菌实验结果显示,相较于AMK溶液,AMK-MVLs混悬液对E. coli、 P. aeruginosa、S. aureus 3种细菌具有更好的抗菌效果。结论 成功制备了一种硫酸阿米卡星多囊脂质体,其粒径分布均匀、包 封率高,释药规律符合Higuchi动力学模型,具有增强的抗菌活性。     

长效利拉鲁肽多囊脂质体的制备及质量评价

目的制备长效利拉鲁肽多囊脂质体(liraglutide-load multivesicular liposomes,Lrg-MVLs),并对其理化性质和体外释放进行了考察。方法采用复乳法制备Lrg-MVLs,以成形性、粒径为评价指标,采用单因素试验优化Lrg-MVLs制备条件。测定了优化处方制备的Lrg-MVLs包封率和粒径,并考察了其体外释放度。结果优化处方制备的Lrg-MVLs平均粒径为8.23μm,包封率为(88.69±0.65)%。体外释放结果显示,Lrg-MVLs体外持续释放达168 h,2 h释放(1.18±0.77)%,无突释现象,体外释放符合Ritger-Peppas模型。结论 Lrg-MVLs呈典型的非同心圆结构,粒径均匀、包封率高,可用于包载Lrg(liraglutide)达到缓慢释放的目的。     

蟾酥提取物长循环脂质体的制备及质量评价

目的研究蟾酥提取物长循环脂质体(chan su long-c ircu lation liposom e,CSLLP)的制备方法,并对其质量进行评价。方法考察不同方法制备CSLLP的包封率,最终确定选用乙醇注入法制备CSLLP,正交设计优化处方,用两亲性聚乙二醇2000-二硬脂酰磷脂乙醇胺(mPEG2000-DSPE)修饰脂质体膜,透射电镜观察形态,激光散射法测定粒径大小及分布,采用葡聚糖凝胶柱层析法和HPLC法测定CSLLP的包封率和渗漏率。结果乙醇注入法制备的CSLLP包封率最高,所得脂质体外观圆整而均匀,渗漏率小,稳定性好,平均粒径为69.8 nm,药物平均包封率为95.54%。结论用乙醇注入法可制备包封率高、稳定性好的CSLLP。     

Preparation and evaluation of N(3)-O-toluyl-fluorouracil-loaded liposomes

This study was aimed at developing a liposome delivery system for a new and potential antitumor lipophilic prodrug of 5-fluorouracil (5-Fu)-N(3)-O-toluyl-fluorouracil (TFu), intended to improve the bioavailability and therapeutic efficacy of 5-Fu by oral and intravenous administration. TFu-loaded liposomes were prepared by a modified film dispersion-homogenization technique, the formulation and manufacture parameters were optimized concerning the drug encapsulation efficiency. TFu-loaded liposomes were characterized according to particle size, size distribution, zeta potential, drug entrapment efficiency, drug loading and physical stability, respectively. In vitro release characteristics, in vivo pharmacokinetic properties and bioavailabilities were also investigated. The formulated liposomes were found to be relatively uniform in size (400.5 +/- 9.6 nm) with a negative zeta potential (-6.4 +/- 0.8 mV). The drug entrapment efficiency and loading were (88.87 +/- 3.25%) and (8.89 +/- 0.19%), respectively. The physical stability experiments results indicated that lyophilized TFu-loaded liposomes were stable for at least 9 months at 4 degrees C. In vitro drug release profile of TFu-loaded liposomes followed the bi-exponential equation. The results of the pharmacokinetic studies in mice indicated that the bioavailability of TFu-loaded liposomes was higher than the suspension after oral administration, and was bioequivalent comparing with TFu 50% alcohol solution after intravenous (i.v.) administration. These results indicated that TFu-loaded liposomes were valued to develop as a practical preparation for oral or i.v. administration.     

Preparation and evaluation of temperature sensitive liposomes containing adriamycin and cytarabine

Temperature sensitive liposomes (TSL) containing adriamycin (ADM) and cytarabine (Ara-C) were prepared. ADM and Ara-C were selected as model compounds of amphiphilic and hydrophilic drug, respectively. Encapsulation efficiency of ADM entrapped into TSL was about twice greater than that of Ara-C. It might be due to different polarity of the drugs. Lipid compositions of TSL had no effect on the encapsulation efficiency of drugs. Thermal behavior of TSL using a differential scanning calorimetry (DSC) was also investigated. Phase transition temperature (T_c) of TSL was dependent on the lipid compositions of TSL.ADM broadened thermogram of TSL but Ara-C did not. However, T_c of TSL was not changed by any drug. Release rate of drugs was highly dependent on temperature. The release profile of ADM was similar to that of Ara-C. The maximum release rate of drugs from TSL was occurred at the near T_c and observed at 39–41°C for DPPC (Dipalmitoylphosphatidylcholine) only, 52–54°C for DSPC (Distearoylphosphatidylcholine) only, 41–43°C for DPPC and DSPC (3∶1), and 43–45°C for DPPC and DSPC (1∶1), respectively. Effect of human serum albumin (HSA) on the release rate of ADM was investigated. HSA had no significant effect on the release of ADM below T_c. However, ADM release from TSL was increased at the near and above T_c. The HSA-induced leakage of drug may result from the interaction of liposomal constituents with HSA structure at the near T_c. From the fact that the release profiles of ADM from freshly prepared TSL and stored TSL for 1 week at 4°C was not changed, the TSL was considered to be stable for at least 1 week at 4°C. Based on these findings, TSL may be useful to deliver drugs to preheated target sites due to its thermal behaviors.     

人参总皂苷脂质体的制备及质量评价

目的制备人参总皂苷(TSPG)脂质体,并进行质量评价。方法采用薄膜分散法、逆相蒸发法、乙醇注入法制备TSPG脂质体,以形态、包封率、载药量为指标筛选制备方法。结果薄膜分散法制备的TSPG脂质体外形规则、光滑、不黏连,包封率、载药量分别为38.70%、3.14%,较其他方法好。结论薄膜分散法制备的TSPG脂质体达到预期目标。     

乙醇注入法制备柚皮素脂质体及其质量评价

目的制备柚皮素脂质体,优化其处方和工艺,并对其相关性能进行评价。方法采用乙醇注入法制备柚皮素脂质体,通过正交设计优化处方工艺;利用马尔文动态光散射粒径测定仪测定其zeta电位和粒径,采用微型凝胶柱离心法分离游离药物和脂质体,HPLC法测定脂质体中柚皮素的包封率。结果确定最佳处方为:磷脂的质量浓度为0.006 g·m L~(-1),胆固醇与磷脂的质量比为1∶3,药脂比为1∶20,缓冲液p H值为7.40,类脂溶液的溶解温度设定为55℃,类脂溶液的溶解时间为25 min。制得的柚皮素脂质体包封率为(80.44±0.98)%,平均粒径为(223±11)nm,Zeta电位为(-35.9±5)m V。结论乙醇注入法制备柚皮素脂质体工艺简单可行,所制备的柚皮素脂质体包封率高、粒径较小、稳定性好。     

Preparation and characterization of solid lipid nanoparticles containing silibinin

The study describes the development of stealth solid lipid nanoparticles (SLNs) as colloidal carriers for silibinin, a drug with very low solubility. Stealth SLNs were constituted mainly of bioacceptable and biodegradable lipids, such as stearic acid and surfactant Brij 78 (polyoxyethylene 20 stearyl ether) and can incorporate amounts of silibinin up to 7.55%. Stealth-loaded SLNs were in the nanometer size range. Thermal analysis (differential scanning calorimetry) showed that silibinin was dispersed in the stealth SLNs at an amorphous state. Release of silibinin from stealth SLNs was very slow. Stealth SLNs were stable without precipitation of silibinin on storage conditions and can be proposed for their parenteral administration.     

掺入不同形式聚乙二醇的大黄素脂质体的制备与评价

目的：制备掺入甲氧基聚乙二醇2000（mPEG2000）、二硬脂酰乙醇胺-聚乙二醇2000（DSPE-PEG2000）、胆固醇-聚乙二醇2000（Chol-PEG2000）3种形式聚乙二醇（Polyethylene glycol,PEG）的大黄素脂质体,并对其制剂学性质与体外释放性能进行评价。方法：采用薄膜分散-超声法制备掺入不同形式PEG的大黄素脂质体,分别为甲氧基聚乙二醇化大黄素脂质体（mPEG-Emo-Lip）、二硬脂酰乙醇胺-聚乙二醇化大黄素脂质体（DSPE-Emo-Lip）、胆固醇-聚乙二醇化大黄素脂质体（Chol-Emo-Lip）;各脂质体采用激光散射法测定粒径,透射电镜扫描法观察形态,微柱离心法考察包封率（entrapped efficiency,EE%）、载药量（eoading capacity,LC）与泄漏率（leakage,LK%）等制剂学性质;采用动态透析法考察各脂质体在pH 7.4、pH 5.8以及含5% FBS的PBS释放介质中的释放性能。结果：3种脂质体的粒径在120~140 nm之间,分布较均匀,其中mPEG-Emo-Lip粒径稍大;各脂质体包封率大于88%,载药量为32.15~32.53 mg·g^-1,泄漏率低;在pH 7.4、pH 5.8以及含5% FBS的PBS释放介质中的释放度均为DSPE-Emo-Lip > mPEG-Emo-Lip > Chol-Emo-Lip。结论：采用薄膜分散-超声法制备含有不同形式PEG的3种大黄素脂质体,均具有较好的制剂学性质,其中Chol-Emo-Lip具有较强的缓释性能。     

共递送柔红霉素与高三尖杉酯碱的叶酸修饰脂质体的制备与质量评价

目的 评估柔红霉素(DNR)与高三尖杉酯碱(HHT)联合用药对HL60细胞增殖的抑制作用;制备叶酸修饰的共递送DNR+HHT的复合脂质体。方法 采用MTT法检测细胞增殖,CompuSyn软件计算DNR与HHT的联合用药指数。以薄膜水化法制备脂质体,在单因素试验基础上,采用Box-Behnken响应面法优化共递送脂质体的处方;通过正交试验设计优化制备工艺。结果 DNR+HHT的联合用药指数为0.69,两者具有协同作用。优选处方为：磷脂10.7μmol·mL^-1,磷脂-胆固醇的摩尔比为4:1,磷脂-DNR的用量比为15:1。优选制备工艺为：水合时间2 h,水合温度40℃,油水比例为2:1。结论 Box-Behnken响应面法结合正交试验设计可有效优化共递送脂质体的处方与制备工艺,所得脂质体的包封率高、粒度均匀。     

Preparation and evaluation of easy energy supply property of medium-chain fatty acids liposomes

To develop an easy-energy-supply agent, medium-chain fatty acids (MCFAs) liposomes were prepared by thin-layer dispersion, freeze-thawing and dynamic high pressure microfluidization (DHPM)-freeze-thawing methods. Results showed that MCFAs nanoliposomes obtained by the novel method (DHPM-freeze-thawing) exhibited a smaller size (72.6?±?4.9?nm), narrower size distribution (PDI?=?0.175?±?0.005), higher zeta potential (?41.27?±?1.16?mV) and entrapment efficiency (45.9?±?6.0%) compared to the other two methods. In the weight-loaded swimming test of the mice, the high-dose group of MCFAs nanoliposomes indicated a significantly longer swimming time (105?±?31?min, p?<?0.05), a lower serum urea nitrogen (839.5?±?111.9?mg/L, p?<?0.05) and blood lactic acid (5.7?±?1.0?mmol/L, p?≤?0.001), and a higher hepatic glycogen (15.0?±?3.6?mg/g, p?≤?0.001) than those of the control group (53?±?13?min, 1153.6?±?102.5?mg/L, 12.5?±?1.9?mmol/L and 8.8?±?3.3?mg/g, respectively). However, no significant difference was found between the high-dose group and MCFAs group. The results suggested that MCFAs nanoliposomes could be used as a potential easy-energy-supply agent.     

Preparation and evaluation of easy energy supply property of medium-chain fatty acids liposomes

To develop an easy-energy-supply agent, medium-chain fatty acids (MCFAs) liposomes were prepared by thin-layer dispersion, freeze-thawing and dynamic high pressure microfluidization (DHPM)-freeze-thawing methods. Results showed that MCFAs nanoliposomes obtained by the novel method (DHPM-freeze-thawing) exhibited a smaller size (72.6?±?4.9?nm), narrower size distribution (PDI?=?0.175?±?0.005), higher zeta potential (-41.27?±?1.16?mV) and entrapment efficiency (45.9?±?6.0%) compared to the other two methods. In the weight-loaded swimming test of the mice, the high-dose group of MCFAs nanoliposomes indicated a significantly longer swimming time (105?±?31?min, p?相似文献   

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。     

联合包载阿霉素和siRNA阳离子脂质体的制备及体外评价

目的制备联合包载阿霉素和siRNA阳离子脂质体并进行体外评价。方法采用薄膜分散法制备载阿霉素阳离子脂质体(doxorubicin cationic liposomes,DCL),与siRNA静电复合得联合载药阳离子脂质体(liposome complexes,lipoplexes);动态激光散射法测定lipoplexes的粒径和zeta电位;透射电镜观察lipoplexes形态;超滤离心法测定lipoplexes中阿霉素和siRNA的包封率;琼脂糖凝胶阻滞实验考察lipoplexes中siRNA的结合能力;荧光显微镜观察MCF-7/ADR细胞对siRNA的摄取情况。结果所制备的lipoplexes外形圆整、分散均匀,当(2,3-二油氧基丙基)三甲基氯化铵与siRNA质量比为20时,其平均粒径为(125.7±2.7)nm,zeta电位为((45.8±1.5)m V,阿霉素包封率为(52.3±2.6)%,siRNA包封率为(88.1±1.8)%,且lipoplexes中siRNA可以紧密结合。与游离siRNA相比,lipoplexes可显著增加MCF-7/ADR细胞对siRNA的摄取。结论联合包载阿霉素和siRNA阳离子脂质体体外性质良好,能增加MCF-7/ADR细胞对siRNA的摄取,可用于小分子化疗药物和siRNA的共输送。     

PCM和TAT双修饰脂质体的制备及心肌靶向性的初步评价

目的 研究心肌特异性靶向肽PCM和穿膜肽TAT双修饰的载荧光探针香豆素-6脂质体的制备工艺,并初步考察其心肌靶向性.方法 采用薄膜分散-超声法,以PCM和TAT为靶头,制备以大豆磷脂、胆固醇、DSPE-mPEG2000为载体材料的载香豆素-6的双修饰脂质体;优化香豆素-6用量、靶头连接方法及靶头用量,以形态、粒径分布、电位、包封率及体外稳定性对脂质体进行表征;考察心肌细胞H9C2对双修饰脂质体的摄取能力,表征其心肌靶向性.结果 PCM和TAT通过插入法连接,当PCM的用量为脂质的3％、TAT的用量为脂质的1％、香豆素-6的用量为20 μg时,所制得的双修饰脂质体的形态圆整,粒径分布为115.7 ±2.91 nm,Zeta电位为-13.1 ±1.81 mV,包封率为83.2％±3.1％,具有良好的体外稳定性,双修饰脂质体的心肌细胞摄取率明显高于未修饰和单修饰的脂质体.结论 双修饰脂质体的制备工艺简单,PCM和TAT双修饰可提高脂质体的心肌细胞靶向性.     

Preparation of microencapsulated liposomes

Liposomal microcapsules were prepared by encapsulating a liposome suspension in a nylon wall formed by the interfacial polymerization technique. The resulting microcapsules were washed in ether to remove the chloroform and cyclohexane. Residual ether was removed by rinsing with distilled water prior to resuspending the microcapsules in aqueous medium. The encapsulation efficiency of the microcapsules toward liposomes was dependent on the lipid composition of the liposomes. The liposomal nylon microcapsules possess sustained release properties when compared with the simple nylon microcapsules.