灯盏花素阳离子脂质体的制备

目的：制备灯盏花素阳离子脂质体和普通脂质体并对其相关性质进行考察。方法：采用薄膜分散法制备灯盏花素脂质体;以包封率为指标,通过正交试验对处方进行优化。考察灯盏花素普通脂质体和阳离子脂质体的体外释放行为。结果：制备的灯盏花素阳离子脂质体性质稳定,包封率为（76.42±1.973）%,平均粒径为（186±35） nm,Zeta电位为（48.9±9.83） mV。灯盏花素普通脂质体和阳离子脂质体的释放过程的拟合方程分别为lnln［1/(1-Q)］=0.779 7lnt-2.318 7(r=0.973 9)和lnln［1/(1-Q)］=0.355 3lnt-3.197(r=0.989 9)。结论：确定了最优处方,制备得到包封率较高且状态稳定的灯盏花素阳离子脂质体。     

灯盏花素脂质体/水分配系数的研究与应用

目的应用脂质体 /水分配系数 ,初步揭示灯盏花素与磷脂分子间相互的作用机理 ,探讨灯盏花素口服吸收机制 ,并且解释一些因素影响灯盏花素脂质体包封率的规律。方法采用平衡透析法测定灯盏花素的脂质体 /水分布系数。结果与灯盏花素的油 /水分配系数随着 pH值的增加而减小相反 ,脂质体 /水分配系数随着pH值的增加而增大 ;磷脂浓度增大 ,脂质体 /水分配系数有增大的趋势。结论药物与磷脂膜的作用除疏水相互作用 (hydrophobicinteraction)外 ,离子间静电、氢键等相互作用占了很大比例 ;初步推测灯盏花素的吸收差可能是因为其吸收有除简单的被动转运外的其它机制 ;实验结果可以用来解释包封率影响因素的一些规律。     

灯盏花素脂质体的制备工艺

目的研究灯盏花素脂质体的制备工艺。方法采用薄膜蒸发-探头超声法和冷冻干燥法制备灯盏花素脂质体,在单因素考察基础上采用正交试验设计。以包封率为评价指标,筛选脂质体制备的最佳工艺条件。冻干品水合后,在电镜下观察灯盏花素脂质体的形态,利用马尔文测定仪测定脂质体的粒径,用RP-HPLC法测定其包封率。结果灯盏花素脂质体的最佳工艺处方为药脂比1∶5,SPC∶CH为2∶1,二氯甲烷用量为10 ml。冻干保护剂蔗糖用量为10%。制备3批脂质体,包封率平均为87.5%,平均粒径为378.3 nm。结论所制脂质体包封率较高,粒径分布较均匀。     

超滤法-HPLC法测定灯盏花素脂质体包封率

目的对灯盏花素脂质体进行质量评价,测定灯盏花素脂质体包封率。方法采用超滤法分离脂质体与游离药物;采用Kromasil ODS柱(200 mm×4.6 mm,5μm),流动相为甲醇乙腈20 mmol.L-1磷酸盐缓冲液(pH值为2.5)(体积比为17∶17∶66),流速为0.8 mL.min-1,检测波长为334 nm,测定药物含量,计算包封率。结果超滤法能很好的将脂质体与游离药物分离,游离药物的平均回收率在95.9%~97.6%,加样回收率在96.4%~97.1%,脂质体不能透过超滤膜;该色谱条件下,灯盏乙素得到良好分离,辅料不干扰测定,灯盏乙素在1.0~40.0 mg.L-1内线性关系良好(r=0.999 9),日内和日间RSD均小于2.0%(n=5),加样回收率在99.7%~100.1%之间,RSD小于1.23%。结论该方法可用于灯盏花素脂质体的质量控制。     

RP-HPLC法测定灯盏花素纳米脂质体药物含量及包封率

目的:建立灯盏花素脂质体药物含量测定及包封率测定的反相高效液相色谱法。方法:色谱柱:Hypersil c12柱(250 mm×4.6 mm,5μm);流动相:乙腈-水-冰醋酸-三乙胺(16:81:2:1);柱温:40℃;流速:1.2 mL·min-1;紫外检测波长:335nm。采用反透析法测定灯盏花素纳米脂质体的包封率。结果:在此色谱条件下灯盏花素与辅料及溶剂峰均得到良好分离,灯盏花乙素在1.0-50.0 μg·mL-1浓度范围内线性关系良好(r=0.9999,n=6),平均回收率为100.3％,日内及日间RSD均小于2.0％(n=5)。结论:该方法准确可靠、简单快速,可用于灯盏花素纳米脂质体药物含量及包封率的测定。     

表面修饰的灯盏花素聚乳酸纳米粒的制备和大鼠体内药动学*

目的:制备灯盏花素聚乳酸纳米粒并对其进行了表面修饰,同时考察了游离药物和纳米药物经大鼠尾静脉注射后在动物体内的药动学。方法:采用自乳化溶剂扩散法制备灯盏花素聚乳酸纳米粒,并用泊洛沙姆188对纳米粒进行表面修饰,采用反相高效液相色谱法(RP-HPLC)测定纳米粒的包封率、载药量和血浆样品中灯盏花素的含量,药时数据采用DASver 1.0药代计算程序处理。结果:载药纳米粒平均粒径为177.2和319.6 nm,多分散指数分别为(0.11±0.01)和(0.12±0.02),平均包封率及载药量分别为(86.9±0.9)%,(8.0±0.2)%和(93.1±0.6)%,(8.5±0.1)%,游离灯盏花素iv后呈二室模型,t1/2β为(0.81±0.14)m in,纳米组则呈一室模型,2种粒径的纳米粒的t1/2β分别为(8.90±0.16)m in(177.2 nm)和(13.90±0.07)m in(319.6 nm)。游离灯盏花素和2种粒径的灯盏花聚乳酸纳米粒的AUC0~t分别为(158.82±69.96),(1 476.25±51.22)和(704.95±25.39)mg.m in.L-1。经t检验,游离药物与纳米药物之间的t1/2β和AUC0~t均有统计学差异(P<0.01)。结论:灯盏花素制成纳米粒后明显增加了药物在动物体内的半衰期,延长了药物在体内的循环时间,且不同粒径的纳米粒对药动学有一定的影响。     

高效液相色谱法测定灯盏乙素血药浓度及其脂质体大鼠药代动力学的评价

目的研究灯盏乙素脂质体及水剂在大鼠体内的血药浓度,考察大鼠灌胃给药后体内药代动力学参数。方法通过大鼠灌胃灯盏乙素水溶液和脂质体后,用高效液相色谱法测定不同时间点的血浆药物浓度,用DAS2.0软件对血药浓度数据拟合分析,比较药动学参数。结果灯盏乙素水剂和脂质体大鼠灌胃给药后,Cmax分别是(15.35±1.37)μg/mL和(22.04±1.67)μg/mL,AUC0-∞分别为(50.03±13.45)μg/(h·mL)和(80.96±15.26)μg/(h·mL),灯盏乙素包衣脂质体大鼠口服给药后药动学呈双室模型特征,与灯盏乙素水剂相比,其脂质体的灌胃AUC0-∞显著提高(P<0.01)。结论本高效液相色谱法对大鼠血浆灯盏乙素测定,稳定性、灵敏度及专属性强,灯盏乙素脂质体可显著提高灯盏乙素的生物利用度。     

紫草素的脂质体制备工艺及其质量评价研究

目的:研究紫草素脂质体的制备方法及质量评价。方法:采用薄膜超声法制备紫草素脂质体,超速离心法测其包封率;以包封率、粒径为指标,采用正交试验设计法优化处方,并对其表面特征、包封率、粒径、Zeta电位进行考察。结果:优化处方制备的脂质体平均粒径为187.73 nm,药物的平均包封率为76.9%,Zeta电位绝对值为38.94 mV,外观圆整,分散均匀。结论:制备的紫草素脂质体包封率较高,粒径小,混悬液体系稳定,为紫草素脂质体的进一步研究奠定基础。     

复方克林霉素脂质体凝胶的制备及体外透皮释药研究

目的制备复方克林霉素脂质体凝胶并考察其粒径分布、包封率及体外透皮特性。方法采用薄膜分散法制备复方克林霉素脂质体,利用透射电镜观察其形态,用激光纳米粒度仪测定其粒径大小及分布,用HPLC法测定其包封率。将脂质体进一步制成凝胶剂后,考察其体外透皮情况。结果复方克林霉素脂质体的粒径在240nm左右,分布均匀,平均包封率为51.24%;脂质体中的克林霉素能缓慢透过大鼠皮肤,缓释效果明显。结论该制剂制备工艺简单,性质稳定,药物包封率较高,定量测定方法简便、准确;药物透皮速率缓慢,释药稳定。     

pH梯度法结合逆向蒸发法制备硫酸多黏菌素E脂质体

目的制备硫酸多黏菌素E脂质体,并对其处方工艺进行研究。方法采用pH梯度法和pH梯度法结合逆向蒸发法制备硫酸多黏菌素E脂质体,用超滤法分离游离药物与脂质体,用HPLC法测定包封率,考察各处方及工艺因素对包封率的影响。结果硫酸多黏菌素E脂质体最佳处方和工艺:磷脂和胆固醇质量比为3∶1,药物与磷脂质量比为1∶20,pH值梯度范围为3.0~5.8,50℃孵育20 min,包封率达70%以上。结论采用pH梯度法结合逆向蒸发法制备的硫酸多黏菌素E脂质体具有较高的包封率。     

HPLC法测定马钱子碱固脂纳米粒冻干粉的包封率和载药量

目的：测定马钱子碱固脂纳米粒冻干粉的包封率和载药量。方法：采用SephadexG-50凝胶柱分离固脂纳米粒和游离马钱子碱,高效液相色谱法测定包封率和载药量,并进行方法学考察。结果：葡聚糖凝胶柱能有效分离固脂纳米粒与游离马钱子碱,平均柱回收率和平均柱加样回收率分别为97．2％和96．4％。马钱子碱固脂纳米粒冻干粉的平均包封率为50．18％,平均载药量为2．11％。结论：该方法简便易行,准确可靠,重复性好,可用于马钱子碱田脂纳米粒冻千粉的载药量和包封率的测定。     

尼莫地平亚微乳包封率的测定

目的:建立测定尼莫地平亚微乳的包封率的方法。方法:本文通过葡聚糖凝胶柱法和透析法分离游离药物,采用高效液相色谱法测定了尼莫地平亚微乳的包封率,并考察了这2种方法的可行性;结果:2种方法测定尼莫地平亚微乳的包封率分别为97.9%和96.8%,回收率分别为98.30%和99.71%,加样回收率分别为98.10%和99.83%。结论:葡聚糖凝胶柱法和透析法可用于亚微乳的包封率的测定。     

葡聚糖凝胶柱色谱法测定阿苯达唑纳米脂质体包封率的方法研究

目的：考察用葡聚糖凝胶柱色谱法测定阿苯达唑纳米脂质体包封率的影响因素。方法：考察大、小2种不同粒径（100～300、50～150μm）的葡聚糖凝胶对样品脂质体的分离效果;以方法回收率和脂质体分离比为综合指标,以凝胶柱内径与葡聚糖填充高度比（A）、洗脱流速（B）及上样量（C）为因素设计正交试验,筛选测定脂质体包封率的最优条件,并进行验证试验。结果：小粒径的葡聚糖凝胶对样品分离效果更好;优选测定条件为A：1.2：5、B：5mL·min-1、C：0.5mL;验证试验中平均脂质体分离比（包封率）为（91.56±0.98）%,平均方法回收率为（98.61±0.44）%（n=3）。结论：所建立的阿苯达唑纳米脂质体包封率测定方法准确、重现性好。     

Distribution of liposomal breviscapine in brain following intravenous injection in rats

AIM: To investigate distribution of breviscapine in brain after intravenous (i.v.) injection of liposomes. METHODS: Breviscapine liposomes were prepared by rotary evaporation-sonication method. Particle size, encapsulation efficiency and stability of liposomes were respectively examined. In vitro drug release was investigated in 0.9% sodium chloride at 37 degrees C. Rats were divided into two groups. Liposomes were given to one group and commercial injection (Injectio Breviscapine) was given to the other at a single dose of 28.1 mgkg(-1) i.v., respectively. Scutellarin in rat brain at different sampling time was determined by RP-HPLC. The brain concentration-time curves of breviscapine liposomes and commercial injection were constructed and pharmacokinetic parameters were calculated and compared by statistic analysis. RESULTS: The average liposome diameter was 735+/-59 nm and encapsulation efficiency was 85.1+/-2.3%. The average accumulative release percentage of breviscapine liposomes in 0.9% sodium chloride was less than 30% within 24h. The mean concentration-time curves of breviscapine liposomes and commercial injection were both fitted to one-compartment model. There are significant difference of parameter T(1/2) and AUC(0-360) between liposome and commercial injection (p<0.05). T(1/2) of breviscapine liposomes and commercial injection were 23.13+/-7.71 and 6.27+/-1.84min, respectively. The brain AUC ratio of breviscapine liposomes to commercial injection was 443.4+/-92.3%. CONCLUSION: Compared with the commercial injection, liposomes delivered more drugs into the brain and have longer elimination time.     

尼莫地平纳米脂质体包封率测定方法的研究

目的　建立尼莫地平纳米脂质体的包封率测定方法。方法　以高效液相色谱法为分析手段 ,采用反透析法测定尼莫地平纳米脂质体的包封率。结果　反透析法透析平衡时间为6h ,游离药物回收率符合要求;此法测得自制尼莫地平纳米脂质体的平均包封率为85.69%±3.13% ,10h内无渗漏,方法重现性好。结论　反透析法便捷、准确 ,适用于脂溶性药物尼莫地平纳米脂质体的包封率测定。     

注射用克拉霉素脂质体的制备及其包封率的测定

目的制备克拉霉素脂质体并建立其包封率的测定方法。方法采用薄膜．超声法制备克拉霉素脂质体。用葡聚糖凝胶柱层析法分离含药脂质体与游离药物，以Tris缓冲生理盐水（TBS）为洗脱液，用高效液相色谱法测定脂质体中克拉霉素的含量。结果柱层析分离方法的药物回收率为99．86％，加样回收率为99．57％，药物含量测定方法的回收率为99．53％，线性范围25-125mg／L。样品的包封率为85％-87．5％。结论薄膜．超声法适合用于制备克拉霉素脂质体。葡聚糖凝胶柱层析法便捷、准确，可用于测定克拉霉素脂质体的包封率。     

Injectable nimodipine-loaded nanoliposomes: preparation, lyophilization and characteristics

The main purpose of this study was to prepare nimodipine-loaded nanoliposomes for injection and evaluate their characteristics after lyophilization. Nimodipine-loaded nanoliposomes were prepared by the emulsion-ultrasonic method with sodium cholesterol sulfate (SCS) as the regulator and then lyophilized by adding different cryoprotectants. SCS was used as a blender of regulator and surfactant and helped to prepare smaller liposomes due to the steric hindrance of the sulfate group. The results showed that nimodipine-loaded nanoliposomes with a 20:1 of egg yolk lecithin PL-100M vs. SCS ratio had a particle size of 86.8±42.007 nm, a zeta potential of -13.94 mV and an entrapment efficiency (EE) of 94.34% and could be stored for 12 days at 25°C. Because of the good bulking effect of mannitol and the preservative effect of trehalose, they were used to obtain suitable lyophilized nanoliposomes. The lyophiles containing 10% mannitol and 20% trehalose had a good appearance and a slightly altered particle size after rehydration. In addition, the lyophilized products were characterized by differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, which confirmed the morphous state of trehalose, mannitol and the mixture. Trehalose could inhibit mannitol crystallization to some extent. The drug release from nanoliposomes before and after lyophilization in pH 7.4 phosphate buffer containing 30% ethanol was also examined and both profiles were found to fit the Viswanathan equation. This means that the drug release was controlled by the pore diffusion resistance.     

Microdialysis for evaluating the entrapment and release of a lipophilic drug from nanoparticles

The aim of the study was to evaluate the microdialysis (MD) as a tool to determine entrapment efficiency and drug release of a lipophilic drug model, diclofenac (DIC), from nanocapsules, nanospheres, and nanoemulsions. Factors that could interfere with the MD probe recovery were investigated: perfusion fluid composition, concentration and form of the drug in the perfusate, and recovery method. DIC entrapment efficiency to nanoparticles and the drug release in phosphate buffer pH 7.4 after different dilutions were evaluated by MD and ultrafiltration/centrifugation (UC). DIC recovery for the 5 μL/min flux was concentration and pH dependent. DIC sodium was used for the recoveries determination since it did not differ from the DIC acid recovery for the same media. DIC entrapment efficiency determined applying both techniques were equivalent and close to 100% for all nanoparticles. In pH 7.4 DIC release from the nanoparticles was partial for the dilution rate 1:1 (v/v), around 50–60%. A complete release was observed from 1:10 (v/v) dilution. Only nanocapsules presented a incomplete release for 1:5 (v/v) dilution, around 86%. MD and UC techniques were equivalent for the evaluation of DIC entrapment efficiency and drug release from the nanoparticles.     

盐酸莫西沙星脂质体的制备及包封率测定方法研究

目的：制备盐酸莫西沙星脂质体,建立盐酸莫西沙星脂质体包封率测定方法。方法：乙醇注入法制备盐酸莫西沙星脂质体,正交试验优选脂质体的最佳处方。采用葡聚糖凝胶柱法、超滤离心法分离脂质体与游离药物,并进行方法学考察,优选出测定盐酸莫西沙星脂质体包封率的方法。结果：盐酸莫西沙星脂质体的最佳处方为：卵磷脂与胆固醇比为 3：1,药脂比为 1：7,水合介质中聚山梨酯20的用量为1%,优化后的包封率为90.73%。葡聚糖凝胶柱法和超滤离心法都能将脂质体与游离药物分离,葡聚糖凝胶柱法的平均柱加样回收率为85.54%~88.15%,超滤离心法的平均加样回收率为94.40%~97.35%。结论：盐酸莫西沙星脂质体的制备工艺稳定,包封率较高。葡聚糖凝胶柱法不适于盐酸莫西沙星脂质体的包封率测定,超滤离心法可高效、准确、方便地测定盐酸莫西沙星脂质体包封率。     

Use of remote film loading methodology to entrap sirolimus into liposomes: preparation, characterization and in vivo efficacy for treatment of restenosis

The main objective of this study was to formulate an effective controlled-release liposomal drug delivery system for sirolimus (SIR), a potent antiproliferative and anti-inflammatory drug, to be used for the treatment of restenosis following local vascular delivery. Liposomes were prepared using remote film loading method and characterized with regard to entrapment efficiency (EE), size distribution and zeta potential. The effects of key formulation and proceeding variables on both EE and drug release were studied using a fractional factorial design. By means of this entrapment technique, 98% SIR incorporation was achieved. Nanoliposomes were found to have average size of 110 nm and zeta potential of -9 mV. Developed formulations were found to have prolonged drug release for up to 3 weeks in vitro; this was best fitted by the Higuchi model. Other scopes of this work were to determine the applicability of sirolimus-loaded nanoliposomes (SIR-L) as drug carriers for the treatment of restenosis and to evaluate the effect of the presence of rigid lipids on the in vivo efficacy of the liposomal carrier of SIR. In vivo studies in balloon injured rat carotid arteries revealed the potential of SIR-loaded liposomes as efficient local and controlled drug delivery systems to reduce restenosis.