混合胶团增溶的环孢素A经小鼠皮肤的渗透作用

目的研究由不同表面活性剂和磷脂所组成的混合胶团(mixedmicelles)对环孢素A经小鼠皮肤给药的渗透促进作用。方法将含药混合胶团溶液封闭性应用于离体或在体小鼠皮肤,测定接收介质和血液中环孢素A含量。结果离体条件下,不同表面活性剂和磷脂所形成的混合胶团的皮肤渗透作用强度为:胆酸钠-磷脂混合胶团>脱氧胆酸钠-磷脂混合胶团>TritonX-100-磷脂混合胶团>Tween-20-磷脂混合胶团。在体条件下,用胆酸钠-磷脂混合胶团后,5h血药浓度达峰值,随后血药浓度缓慢下降。结论混合胶团在水溶液状态下对大分子难溶药物环孢素A具有一定的皮肤促渗效果。     

界面活性剂对阿斯匹林片剂溶出速度的影响及其机制的研究

本文考察了三种不同类型界面活性剂月桂醇硫酸钠(SDS),吐温-80(TEN)及十六烷基三甲基溴化铵(CAB),对难溶性固体药物阿斯匹林(ASPN)片剂溶出速度的影响,并进一步探讨了其作用机制。实验表明界面活性剂CAB和TEN对ASPN具有改善润湿及反絮凝作用,可明显增加水中ASPN的溶解及其片剂的溶出,胶团增溶作用经测定是很有限的,不能说明ASPN水中溶解的显著增加。界面活性剂SDS对ASPN的润湿、增溶及其片剂的溶出均没有明显作用。认为与界面活性剂及药物分子的结构和性质密切相关。     

环孢素A混合胶团的制备及质量评价

目的：筛选环孢素A（cyclosporine A，CYA）脱氧胆酸钠/磷脂混合胶团的制备工艺，并初步考察其性质。方法：利用正交试验设计考察了制备所需的载体质量比、温度及水合介质对载药量、包封率的影响。结果：在胆酸钠与磷脂的质量比为1：1，反应温度为60℃和以水为水合介质的条件下，所得到的包封率可达90％以上，载药量达到4％以上，平均粒径约为180nm。结论：通过正交设计得到了高包封率和高载药率的环孢素A混合胶团。     

潜溶剂和环糊精对难溶性药物的联合增溶作用

目的研究潜溶剂和环糊精对难溶性药物的联合增溶作用。方法采用相溶解度法研究药物在不同混合溶剂中的相溶解度，利用已建立的数学模型对这种联合增溶作用作出评价和解释，非线性回归分析估计模型参数。结果两个难溶性药物的增溶模型判定系数R^{2分别为0.993和0.992，拟合效果很好，溶解度的实测值和模型预测值一致。结论该数学模型可以用于解释和预测潜溶剂和环糊精对难溶性药物的联合增溶作用。}     

环孢素脂质微粒经小鼠皮肤给药的渗透机理研究

目的　研究普通纳米脂质体、柔性纳米脂质体及胆酸钠-磷脂混合胶团对环孢素经小鼠皮肤给药的渗透机理。方法　将含药载体非封闭性应用于离体或在体小鼠皮肤,测定了皮肤、接收介质和血液中环孢素含量。结果 离体条件下,应用柔性纳米脂质体和混和胶团后均能在接收液中检测到药物,但普通脂质体却不能。在体条件下,应用柔性纳米脂质体后8 h血药浓度到达峰值,而应用普通脂质体和混合胶团后在血中几乎未检测到药物。结论 柔性纳米脂质体在皮肤水合压力下发生变形,携药透过皮肤;普通脂质体主要与皮肤发生融合产生蓄积作用;混合胶团在水溶液状态下发挥其渗透促进作用。     

注射剂的新型赋形剂—胆盐／卵磷脂混合胶束系统

胆盐／卵磷脂混合胶事系统（BS／PC－MMS）对难溶性药物具强增溶能力,从而可提高药效,它已被用作非肠道给药的载体。综述BS／PC－MMS的增溶原理、作为注射剂赋形剂所起的各种作用及其在药剂其它方面的用途。     

制剂新技术在水难溶性药物中的应用研究进展

目的:了解制剂新技术在水难溶性药物中的应用研究进展。方法:根据文献,综述了水难溶性药物的增溶新技术、缓/控释制剂新技术、增溶-缓释制剂新技术等方面的研究现状。结果:增溶新技术包括合成水溶性前体药物、主药分子结构中导入亲水基团、合成磷脂复合物、加入嵌段共聚物增溶剂、制成微乳等;缓/控释制剂新技术包括骨架型制剂和渗透泵型制剂;增溶-缓释制剂新技术包括固体分散体制剂、包合物制剂和固体脂质纳米粒制剂。结论:增溶新技术、缓/控释制剂新技术、增溶-缓释制剂新技术的应用较好地改善了水难溶性药物吸收差、生物利用度低的不足,发展前景良好。     

自微乳化释药系统与液固压缩技术在难溶性中药制剂中的联合应用

药物的难溶性严重影响药物的生物利用度,也严重影响药物制成各类制剂。如何增加中药难溶性成分的溶解度,改善其生物利用度,一直是药剂学研究的重要内容。对于难溶性药物来说,药物只有处于溶解状态下,才能表现出较好的溶出和生物利用度。自微乳化释药系统和液固压缩技术均有很好的增溶作用,而且液固压缩技术使药物以无定形或分子状态给药,两者联合应用,可以显著提高药物的溶出度和生物利用度,为中药增溶领域提供一种新的思路与方法。     

混合胶团作为脂质体前体亲淋巴药物的载体

磷脂酰胆碱-胆酸盐的混合胶团是一种胶态药物载体,有可能将药物经皮下注射靶向淋巴系统。按照Steffen and Schimidt所述方法制备混合胶团(磷脂酰胆碱浓度为30.8mg/     

全反式维A酸磷脂混合胶团注射剂的制备全反式维A酸磷脂混合胶团注射剂的制备

目的增加维A酸在水中的溶解度,制备维A酸磷脂混合胶团注射剂浓缩液;提高维A酸的生物利用度。方法采用构建磷脂-胆盐组成的磷脂混合胶团对维A酸进行增溶;利用相图及浊度法筛选处方;通过电镜及粒径测定的方法对维A酸浓缩液水分散体中的胶团粒子进行初步研究。结果维A酸磷脂混合胶团注射剂常温避光放置稳定。维A酸能以混合胶团的形式较好地分散于水中,水分散体中粒子平均粒径为17.8 nm,多相分散系数0.495,zeta电位-16.5 mV,所形成的分散体系室温避光条件下放置稳定。结论该方法可用于制备稳定的维A酸注射剂。     

Solubilization and pharmacokinetic behaviors of sodium cholate/lecithin-mixed micelles containing cyclosporine A

The purpose of this study was to investigate the solubilization capacity of sodium cholate/lecithin-mixed micelles and to evaluate the potential of mixed micelles as a carrier of cyclosporine A for intravenous infusion. The mixed micelles were prepared by coprecipitation technique. The formulation components and preparation procedures, which may affect the solubilization of cyclosporine A, were studied. The dilution stability of cyclosporine A-containing mixed micelles was investigated. Pharmacokinetic behaviors of mixed micelles in rabbits after intravenous infusion were compared with Sandimmun. Results showed the strategies to increase the solubility of cyclosporine A include lowering the molar ratio of sodium cholate to lecithin, increasing the concentration of lecithin, and reducing the ionic strength of the dispersion medium and temperature. The largest solubility was found to be 5.42 +/- 0.16 mg/ml. The leakage of mixed micelles in 5% glucose (5.84%) was much less than that in saline solution (36.7%). The relative bioavailability of mixed micelles versus Sandimmun was 112 +/- 20%, and statistical analysis demonstrated both preparations were bioequivalent. Sodium cholate/lecithin-mixed micelles are promising carriers in the intravenous delivery of cyclosporine A, considering their capability of large-scale production and low-toxic property.     

Solubilization and Pharmacokinetic Behaviors of Sodium Cholate/Lecithin-Mixed Micelles Containing Cyclosporine A

The purpose of this study was to investigate the solubilization capacity of sodium cholate/lecithin-mixed micelles and to evaluate the potential of mixed micelles as a carrier of cyclosporine A for intravenous infusion. The mixed micelles were prepared by coprecipitation technique. The formulation components and preparation procedures, which may affect the solubilization of cyclosporine A, were studied. The dilution stability of cyclosporine A-containing mixed micelles was investigated. Pharmacokinetic behaviors of mixed micelles in rabbits after intravenous infusion were compared with Sandimmun®. Results showed the strategies to increase the solubility of cyclosporine A include lowering the molar ratio of sodium cholate to lecithin, increasing the concentration of lecithin, and reducing the ionic strength of the dispersion medium and temperature. The largest solubility was found to be 5.42 ± 0.16 mg/ml. The leakage of mixed micelles in 5% glucose (5.84%) was much less than that in saline solution (36.7%). The relative bioavailability of mixed micelles versus Sandimmun® was 112 ± 20%, and statistical analysis demonstrated both preparations were bioequivalent. Sodium cholate/lecithin-mixed micelles are promising carriers in the intravenous delivery of cyclosporine A, considering their capability of large-scale production and low-toxic property.     

基于分子对接技术的三元混合胶束对多西他赛的增溶效应及安全性

目的 为提高抗肿瘤药物多西他赛的水溶性,制备磷脂-胆酸钠-Soluplus?三元混合胶束包载多西他赛,结合分子对接仿真技术研究三元混合胶束的结构及形成机制.方法 采用薄膜分散法制备Soluplus?胶束、磷脂-胆酸钠二元混合胶束、磷脂-胆酸钠-Soluplus?三元混合胶束;采用芘荧光探针法测定不同胶束的临界胶束浓度值...     

Preparation and <Emphasis Type="Italic">in vitro</Emphasis> evaluation of povidone-sodium cholate-phospholipid mixed micelles for the solubilization of poorly soluble drugs

Mixed micelles made of polyvinylpyrrolidone (PVP), sodium cholate, and phospholipids were prepared to improve the solubility of poorly water-soluble drugs. Sylibin, a drug used in treating liver diseases, was incorporated into the mixed micelles. The formulation of sylibin containing PVP-sodium cholate-phospholipid mixed micelles with an optimized composition (PVP/sodium cholate/phospholipid/silybin = 3:3:4:1∼2 by weight) was obtained based on the study of pseudoternary phase diagrams. The critical micelle concentration was used to evaluate the micellar stability towards dilution. The results showed that addition of PVP to sodium-cholate-phospholipid mixed micelles increased stability. The solubility of sylibin in PVP-sodium cholate-phospholipid mixed micelles was higher than that in pure water or in sodium cholate-phospholipid mixed micelles. In a stability study, we found that PVP-sodium cholate-phospholipid mixed micelles showed good stability. After 3 months storage at 40°C, just 2.6% sylibin was lost with only minor changes of the particle size when compared to a reference formulation containing sodium cholate and phospholipid mixed micelles. In addition, the developed formulation significantly improved in vitro drug release. The time required to release 50% sylibin (t50%) from sodium cholate and phospholipid mixed micelles was 326 h, while the t50% from PVP-sodium cholate-phospholipid mixed micelles was only 51.1 h. Our results suggest that these mixed micelles might have significant potential application to the biomedical field.     

Study of partition of nitrazepam in bile salt micelles and the role of lecithin

The effect of trihydroxy (sodium cholate and sodium glycocholate) and dihydroxy (sodium deoxycholate and sodium glycodeoxycholate) bile salt micelles on the spectrophotometric properties and on the solubility of nitrazepam in aqueous solution, at 25.0 degrees C and at ionic strength 0.1 M in sodium chloride, has been assessed. From the results obtained it was possible to calculate the partition coefficients (Kp) of nitrazepam between aqueous and micellar phases. The partition coefficients of nitrazepam have also been determined in mixed micelles of cholate or deoxycholate with lecithin (egg yolk phosphatidylcholine), which were used as a model of the gastrointestinal tract. Drug partition was found to depend on the bile acid (number of hydroxyl groups and conjugation with glycine), and our data indicate further that addition of lecithin to bile salt micelles decreases the values of the partition coefficients in the mixed micelles at physiological pH.     

Mixed micelle proliposomes for preparation of liposomes containing amphotericin B, in-vitro and ex-vivo studies

The aim of this work was to produce a form of injectable liposomes containing amphotericin B derived from mixed micelle proliposomes. Mixed micelles were derived from a mixture of lecithin/sodium cholate in aqueous media. The solubility of amphotericin B in proliposomes was studied as a function of lipid composition (total lipid concentration, molar ratio of lecithin/sodium cholate), and the dispersion media (pH, ionic strength, presence or absence of human serum albumin), and the temperature. The data show that micelle-->liposome transformation occurs during the dilution of proliposomes containing amphotericin B. These transformations could be followed via transmission electron microscopy (TEM). Data related to dilution of proliposomes as well, show that under no circumstance there occurs any precipitation that might be assigned to the decreased solubility of amphotericin B. These indicate that the incorporated drug also participates during the transformation of the proliposomes into liposomes. It is thus concluded that mixed micelle proliposomes are prime candidates for the production of a form of injectable amphotericin B in liposomes.     

Influence of Drug Lipophilicity on Drug Release from Sclera After Iontophoretic Delivery of Mixed Micellar Carrier System to Human Sclera

Mixed micelles prepared using sodium taurocholate (TA) and egg lecithin (LE) were previously found to be an effective carrier for sustained release of a poorly water-soluble drug in transscleral iontophoretic delivery. The objectives of the present study were to investigate the effects of drug lipophilicity upon micellar carrier solubilization potential and drug release profiles from the sclera after iontophoretic delivery of model lipophilic drugs dexamethasone (DEX), triamcinolone acetonide (TRIAM), and β-estradiol (E2β) with a mixed micellar carrier system of TA–LE (1:1 mole ratio). In this study, the micellar carrier system was characterized for drug solubilization. The micelles encapsulating these drugs were evaluated for transscleral passive and 2-mA iontophoretic delivery (both cathodal and anodal) and drug release from excised human sclera in vitro. The results show that drug solubility enhancement of the micellar carrier system increased with increasing drug lipophilicity. The more lipophilic drugs E2β and TRIAM displayed slower drug release from the sclera compared with the less lipophilic drug DEX after iontophoretic drug delivery with the mixed micelles. These results suggest that the combination of transscleral iontophoresis and micellar carriers is more effective in sustaining transscleral delivery of the more lipophilic drugs studied in this investigation. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:480–488, 2013     

Solubilization behavior of poorly soluble drugs with combined use of Gelucire 44/14 and cosolvent

Gelucire 44/14 is a surface-active excipient that can solubilize poorly soluble drugs. We investigated its solubilization behavior when coexisting with dimethylacetoamide (DMA) or dimethylsulfoxide (DMSO), both of which are also expected to enhance drug solubility. Gelucire was confirmed to form micelles by surface tension and fluorescence measurements both in water and water/cosolvent mixtures. Light-scattering measurements revealed that DMA and DMSO affect the micellar morphology in a different manner. DMA helped form large structures by being entrapped in the hydrophobic region of the micelles and/or inducing the aggregation. DMSO was likely to be anchored to the interfacial layer and did not induce micelle growth. Two model drugs, phenytoin and indomethacin, were employed to observe the solubilization behavior of poorly soluble drugs in Gelucire/cosolvent mixtures. The solubility of these drugs in the mixtures could be explained very well by using the new solubility model introduced in this article. Addition of cosolvents to the Gelucire solution did not enhance the solubility very much, and thus the combined use of cosolvents with Gelucire offered only little advantage from the viewpoint of solubility.     

Mixed micelles made of poly(ethylene glycol)-phosphatidylethanolamine conjugate and d-alpha-tocopheryl polyethylene glycol 1000 succinate as pharmaceutical nanocarriers for camptothecin

Micelles from the mixture of poly(ethylene glycol)-phosphatidyl ethanolamine conjugate (PEG-PE) and d-alpha-tocopheryl polyetheyene glycol 1000 succinate (TPGS) were prepared loaded with the poorly soluble anticancer drug camptothecin (CPT). The solubilization of CPT by the mixed micelles was more efficient than with earlier described micelles made of PEG-PE alone. CPT-loaded mixed micelles were stable upon storage and dilution and firmly retained the incorporated drug. The cytotoxicity of the CPT-loaded mixed micelles against various cancer cells in vitro was remarkably higher than that of the free drug. PEG-PE/TPGS mixed micelles may serve as pharmaceutical nanocarriers with improved solubilization capacity for poorly soluble drugs.     

Biorelevant dissolution media: aggregation of amphiphiles and solubility of estradiol

Biorelevant dissolution media containing bile salt and lecithin at concentrations appropriate for fed and fasted state are useful when testing oral solid formulations of poorly water-soluble drugs. Dilution of amphiphile solutions affects the aggregation state of the amphiphiles because bile salt is partitioned between the aqueous phase and the aggregates. The aim of the investigation was to study the effect of dilution on the size distribution of aggregates and its effect on the solubilization capacity. Clear buffered solutions of four intestinal amphiphiles (sodium glycocholate, lecithin, monoolein, and oleic acid) and a combination of these were prepared at high bile salt concentration. Micelles in the glycocholate solutions decreased in size when diluted. The addition of insoluble amphiphiles led to bigger micelles with no clear correlation between size of the micelles and amphiphile concentration. Dilution of the two- and four component media caused enlargement of the mixed micelles and formation of vesicles. The solubility of estradiol in the buffer solution was increased with addition of the amphiphiles. A good correlation (R(2) = 0.987) was found between estradiol solubility and mass concentration of the amphiphiles. The results demonstrate that, in the case of estradiol, the concentration of amphiphiles rather than the aggregation state determines the solubilization capacity of the medium.