肺靶向羟基喜树碱脂质体的制备及其在小鼠体内的组织分布研究

目的： 研究羟基喜树碱脂质体的制备方法并考察其肺靶向及在小鼠体内的分布。方法： 采用薄膜分散－冻融法制备,添加D-甘露糖和十八胺修饰可得到肺靶向羟基喜树碱脂质体;用HPLC法测定给药后小鼠体内不同组织中的药物浓度。结果： 制得的脂质体平均粒径大于2 μm,表面电荷为+21.5 mV,包封率大于65%,稳定性好,符合要求。羟基喜树碱脂质体和注射液经小鼠尾静脉给药后,脂质体主要被肺摄取,在肺部停留的时间较普通注射剂显著延长,其相对摄取率r_e为60.72,脂质体组的肺靶向效率t_e为17.57。结论： 本实验制得羟基喜树碱脂质体具有较高包封率及稳定性,在小鼠肺部浓度高、滞留时间长,能达到肺靶向目的。     

肺靶向阿奇霉素脂质体的制备及其在小鼠体内的分布

目的研究肺靶向阿奇霉素阳离子脂质体的制备方法并考察其在小鼠体内的分布。方法利用旋转薄膜-冻融法制备肺靶向阿奇霉素脂质体。用高效液相色谱法测定给药后小鼠体内各组织中的药物浓度。结果制得的脂质体平均粒径为6.582 μm，表面电荷为+19.5 mV，包封率大于75%，稳定性好。药物体外释药符合Higuchi方程。小鼠尾静脉给药后，阳离子脂质体主要被肺摄取，在肺部的滞留时间明显延长，AUC值约为阿奇霉素溶液的8.4倍。结论采用薄膜-冻融法，添加十八胺可制得具有较高包封率及稳定性的阿奇霉素阳离子脂质体，在小鼠肺部的分布优于注射液，能达到肺靶向目的。     

脒修饰的包载荧光探针香豆素-6脂质体的制备

目的研究3,5-二-十五烷氧基苯甲脒(DBH)修饰的香豆素-6脂质体的制备工艺,并初步考察该脂质体的体外释放性能和肾小球靶向性。方法首先合成DBH。再以其为配基,胆固醇、大豆磷脂为载体材料,采用薄膜分散-超声法制备脒修饰的载香豆素-6荧光探针脂质体,考察其粒径分布、Zeta电位、包封率及体外累积释药率。结果脒基修饰的香豆素-6脂质体形态圆整,粒径分布为120.7±2.4 nm,Zeta电位为12.6±1.6 m V,包封率为99.7%±1.8%,体外的48 h累积释药量小于2%。结论脒基修饰的香豆素-6脂质体的制备工艺简便易操作,包封率高,性质稳定。     

影响盐酸川芎嗪脂质体包封率各因素分析

目的:采用薄膜分散法合并硫酸铵梯度法制备盐酸川芎嗪脂质体,考察各因素对包封率的影响。方法:用HPLC法测定包封率,考察了磷脂和胆固醇用量比例,脂质和十八胺用量,透析时间,硫酸铵浓度以及载药温度对包封率的影响。结果:脂质体的包封率随磷脂-胆固醇用量比例的提高而提高,最高达54．8％;并随脂质用量增大而增大;适量的十八胺用量以及硫酸铵浓度有利于提高包封率;最合适的栽药温度为37℃。结论:薄膜分散法合并硫酸铵梯度法在适当的条件下可制得包封率较高的盐酸川芎嗪脂质体。     

紫杉醇脂质体的制备及质量考察

目的:制备紫杉醇脂质体并考察其质量。方法:以薄膜分散法制备脂质体;采用高效液相色谱法测定其中主药的含量并计算包封率及体外释放度。结果:所制脂质体粒径为70～150nm;紫杉醇检测浓度的线性范围为0.3～75μg·mL-1(r=0.9998),平均回收率为100.3%(RSD=1.16%,n=3);包封率约为96.46%;体外释药符合Higuchi方程,具有缓释性。结论:薄膜分散法适于制备紫杉醇脂质体;离心法能够准确快速测定脂质体包封率;该制剂体外缓慢释药。     

羟基喜树碱脂质体的制备及质量评价研究

目的:制备羟基喜树碱(HCPT)脂质体,并对其质量进行评价.方法:采用薄膜分散-高压乳匀法制备羟基喜树碱脂质体;用激光粒度分析仪测定其Zeta电位、粒径大小;考察其在0.9%NaCl溶液、水、5%葡萄糖溶液中8 h的稳定性;用凝胶柱层析法考察包封率;采用薄膜透析法考察体外释药性质.结果:羟基喜树碱脂质体Zeta电位为(-33.1±1.3) mV,平均粒径(182.5±5.6) nm,8 h内在水、5%葡萄糖溶液中稳定性良好;包封率(91.2±1.2)%;体外释药曲线符合Higuchi方程Q=1.291 6t1/2 0.309 8,r=0.980 3.结论:本试验制备的羟基喜树碱脂质体稳定性好,大小均匀, 包封率高,并具有延缓药物释放的性质.     

甘草酸二铵脂质体的制备及其性质的研究

目的:研究甘草酸二铵阳离子脂质体的制备方法和脂质体的性质。方法:采用均匀设计筛选最佳处方,逆相蒸发法制备甘草酸二铵脂质体;葡聚糖凝胶柱法测定其包封率;用透射电镜观察脂质体的外观形态,马尔文测定仪测定脂质体的粒径和Zeta电位;并用溶出度第3法考察了脂质体的释放规律。结果:制得脂质体的包封率约为(56±1．54)%(n=3);脂质体的形态为粒径均匀的球形或近球形,粒径为(183±9)nm(n=3),Zeta电位为(22．8±6)mV(n=3);脂质体的体外释药符合Higuchi方程;具有较好的稳定性。结论:采用逆相蒸发法,添加十八胺可制得具有较高包封率及稳定性的甘草酸二铵阳离子脂质体,制得脂质体的体外释放具有缓释特点。     

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.     

结肠癌细胞及线粒体双级靶向脂质体的处方工艺筛选研究

目的：研究结肠癌细胞及线粒体双级靶向脂质体（HA/TPP-TPGS LP/DOX）的最佳处方工艺。方法：用薄膜分散法结合微孔滤膜法制备;以细胞抑制率为指标,用MTT法筛选最佳聚脂比;以包封率为指标,用正交试验筛选最佳胆脂比、药脂比和超声时间;以粒径为指标,筛选最佳透聚比;以复溶后粒径和包封率为指标,筛选冻干保护剂的品种;用荧光显微镜和流式细胞术考察脂质体的靶向性;用透析法考察体外释药行为。结果：最佳处方是聚脂比1∶7、胆脂比1∶10、药脂比1∶15、超声时间15 min、透聚比2∶1,冻干保护剂为蔗糖。制备的脂质体呈类球形,粒径（142.20±0.54）nm,Zeta电位-（24.06±0.25）mV,包封率（98.20±0.18）%,稳定性高,有双级靶向性和体外药物缓释性。结论：本研究制备的脂质体有包封率高、粒径小、双级靶向性和缓释性等优点,为进一步研究奠定了基础。     

甘露糖修饰姜黄素/人参皂苷Rb1脂质体的处方优选及体外脑靶向性评价

目的:优化甘露糖(MAN)修饰姜黄素(Cur)/人参皂苷Rb1(GS-Rb1)共载脂质体(Lip)的处方,考察其体外靶向能力.方法:通过薄膜分散法-硫酸铵梯度法制备MAN-Cur/GS-Rb1-Lips,以包封率为考察指标,采用星点设计响应面法确定MAN-Cur/GS-Rb1-Lips最佳处方.采用荧光显微镜法考察了 ...     

Effect of formulation design and freeze-drying on properties of fluconazole multilamellar liposomes

Fluconazole-entrapped multilamellar liposomes were prepared using the thin-film hydration method. The effects of cholesterol molar ratio, charge-inducing agents, and α-tocopherol acetate on encapsulation efficiency values and in vitro drug release of multilamellar liposomes were studied. Freeze-dried liposomal products were prepared with or without cryoprotectants. Results showed that incorporation of stearylamine resulted in an increased entrapment of fluconazole, whereas incorporation of dicetyl phosphate decreased the drug entrapment efficiency. The incorporation of α-tocopherol acetate into fluconazole multilamellar liposomes resulted in the increase of entrapment efficiency of fluconazole liposomes. In vitro release studies revealed that incorporation of cholesterol into multilamellar liposomal formulations decreased drug permeability from formulations. Positively charged fluconazole multilamellar liposomes gave rise to a slow release rate compared to neutral liposomes whereas negatively charged fluconazole liposomes showed a rapid release rate. Physical stability studies showed that lyophilized cake of liposomes without cryoprotectants was compact and difficult to reconstitute compared to fluffy easily reconstituted cakes upon using cryoprotectants. Fluconazole retained in freeze-dried liposomes without cryoprotectants was 63.452% compared to 91.877% using three grams of trehalose as a cryoprotectant per gram lipid in positively charged multilamellar liposomes. Physical stability studies showed superior potentials of the lyophilized product after reconstitution in comparison with those of a solution product.     

Development, characterization and in vitro assessement of stearylamine-based lipid nanoparticles of paclitaxel

The objective of the study was to design and evaluate a solid lipid nanoparticle (SLN) drug delivery system for delivery of paclitaxel. Components of the SLN were lipid (stearylamine) and surfactants (Pluronic F68 and Soya lecithin). The paclitaxel loaded nanoparticles were prepared by a modified solvent injection method. Experiments were carried out with excipients, where surfactants, lipid and drug molar ratios were varied to optimize the formulation characteristics. The in vitro drug release profile from the nanoparticles followed a diffusion controlled mechanism. The modified solvent injection method ensured high entrapment efficiency (approximately 75%), produced smaller, stable nanoparticles with a narrow size distribution and proved to be a reproducible and fast production method. The present study describes the feasibility and suitability of stearylamine based SLN produced using a mixture of surfactants to develop a clinically useful system with targeting potential for poorly soluble antineoplastic drugs.     

姜黄素-汉防己碱共递送抗病毒复方脂质体的构建

目的：制备寡聚透明质酸衍生物 oHA 修饰的姜黄素－汉防己碱中药抗病毒脂质体,并对其进行体外释放和稳定性研究。方法用薄膜分散法制备了寡聚透明质酸衍生物修饰的姜黄素－汉防己碱脂质体,以粒径和包封率作为两个重要的参考指标,使用粒度仪测定了粒径,使用紫外分光光度法测定包封率。结果用 Box －Be-hnken 效应面优化法确定了最佳磷脂胆固醇比为2．5∶1,最佳姜黄素－汉防己碱比例为2．8∶1,寡聚透明质酸衍生物的用量为1．80％,通过最佳处方制备的脂质体的粒径是201．06 nm,包封率是70．94％。结论制备的脂质体具有良好的稳定性,均匀的粒径分布,证明了脂质体具有良好的体外释放活性,良好的稳定性,为进一步研究抗病毒联合机制奠定基础。     

月桂酸二乙醇酰胺修饰利福喷丁脂质体的制备、性质及肺部给药

目的制备表面活性剂修饰利福喷丁(RIF)脂质体，进行该脂质体水化性能、载药量、释药速度和肺部给药研究。方法采用薄膜超声法制备利福喷丁脂质体，比较月桂酸二乙醇酰胺(LDEA)，Tween 80和azone修饰利福喷丁脂质体的形态、包封率、释药速度和离体猪肺膜透过性，通过纤支镜进行肺部给药研究。结果RIF-LDEA脂质体粒径在15～50 nm，包封率为83.0%，表观透膜系数Kp为44.29；LD₅₀为675 mg·kg^-1。结论LDEA修饰使利福喷丁脂质体的载药量增加1倍、释药速度的可调性强及安全性好。经纤支镜介导灌注给药治疗肺内膜结核的效果显著。     

槲皮素前体脂质体的质量考察

目的制备液体型槲皮素前体脂质体,并对制剂质量进行考察。方法采用一种新型前体脂质体制备方法制备液体型槲皮素前体脂质体,将脂质体膜材和药物等以一定比例溶于分散介质中,形成一种无水的澄明溶液。考察其水合后粒子形态、粒径、电位、包封率及自组装速度等理化性质,并评价其体外释药性质。结果槲皮素前体脂质体遇水即可快速自组装成纳米级含药脂质体混悬液,水合后形态多为类球形,平均粒径为228.7nm,Zeta电位为21.2 mV,包封率可达90%以上,体外释药符合Higuchi方程。结论槲皮素口服前体脂质体制备工艺简单可行,包封率高,具有一定的缓释效果。     

2-甲氧基雌二醇脂质体的质量评价

目的:对2-甲氧基雌二醇(2-ME)脂质体进行质量评价. 方法:用乙醚注入法制备2-ME脂质体,与原料药相比,体外释药情况的考察. 并从粒径包封率两个方面进行稳定性考察. 结果:体外释药试验表明,与原料药相比,脂质体无突释现象且持续释药, 4℃存放两周稳定性较好. 结论:用乙醚注入法制备的2-ME脂质体质量稳定,可为2-ME的临床应用提供一种新剂型.     

Development and evaluation of inhalational liposomal system of budesonide for better management of asthma

Budesonide is a corticosteroid used by inhalation in the prophylactic management of asthma. However, frequent dosing and adverse effects (local and systemic) remain a major concern in the use of budesonide. Liposomal systems for sustained pulmonary drug delivery have been particularly attractive because of their compatibility with lung surfactant components. In the present investigation, pulmonary liposomal delivery system of budesonide was prepared by film hydration method and evaluated for sustained release. Various parameters were optimized with respect to entrapment efficiency as well as particle size of budesonide liposomes. For better shelf life of budesonide liposomes, they were freeze dried using trehalose as cryoprotectant. The liposomes were characterized for entrapment efficiency, particle size, and surface topography; in vitro drug release was evaluated out in simulated lung fluid at 37° at pH 7.4. The respirable or fine particle fraction was determined by using twin stage impinger. The stability study of freeze dried as well as aqueous liposomal systems was carried out at 2-8° and at ambient temperature (28±40). The freeze dried liposomes showed better fine particle fraction and drug content over the period of six months at ambient as well as at 2-8° storage condition compared to aqueous dispersion of liposomes.     

Design and Evaluation of Liposomal Formulation of Pilocarpine Nitrate

Prolonged release drug delivery system of pilocarpine nitrate was made by optimizing thin layer film hydration method. Egg phosphatidylcholine and cholesterol were used to make multilamellar vesicles. Effects of charges over the vesicles were studied by incorporating dicetylphosphate and stearylamine. Various factors, which may affect the size, shape, encapsulation efficiency and release rate, were studied. Liposomes in the size range 0.2 to 1 µm were obtained by optimizing the process. Encapsulation efficiency of neutral, positive and negatively charged liposomes were found to be 32.5, 35.4 and 34.2 percent, respectively. In vitro drug release rate was studied on specially designed model. Biological response in terms of reduction in intraocular pressure was observed on rabbit eyes. Pilocarpine nitrate liposomes were lyophilized and stability studies were conducted.