A Mixed Micellar Formulation Suitable for the Parenteral Administration of Taxol

Taxol is a promising antitumor agent with poor water solubility. Intravenous administration of a current taxol formulation in a non-aqueous vehicle containing Cremophor EL may cause allergic reactions and precipitation upon aqueous dilution. In this study a novel approach to formulate taxol in aqueous medium for i.v. delivery is described. The drug is solubilized in bile salt (BS)/phospholipid (PC) mixed micelles. The solubilization potential of the mixed micelles increased as the total lipid concentration and the molar ratio of PC/BS increased. Precipitation of the drug upon dilution was avoided by the spontaneous formation of drug-loaded liposomes from mixed micelles. The formulation can be stored in a freeze-dried form as mixed micelles to achieve optimum stability, and liposomes can be prepared by simple dilution just before administration. As judged by a panel of cultured cell lines, the cytotoxic activity of taxol was retained when formulated as a mixed-micellar solution. Further, for the same solubilization potential, the mixed-micellar vehicle appeared to be less toxic than the standard nonaqueous vehicle of taxol containing Cremorphor EL.     

胆酸钠/磷脂混合胶团对环孢素A的增溶作用研究

目的研究胆酸钠/磷脂混合胶团对难溶性多肽环孢素A(CyA)的增溶作用.方法采用共沉淀法制备胆酸钠/磷脂混合胶团,并对影响增溶作用的处方及工艺进行考查.结果相同胆酸钠浓度条件下,混合胶团对CyA的增溶能力远大于胆酸钠胶团,增大混合胶团中的磷脂用量或者降低胆酸钠/磷脂(摩尔比)均有利于提高混合胶团对药物的增溶能力.升高水合温度,增加水合介质的离子强度,加入抗氧化剂维生素E(VE)及胆固醇,均不同程度的降低了混合胶团的增溶能力.通过优化各个影响因素可获得最大的增溶量(＞5mg/mL),增加CyA溶解度100倍以上.结论胆酸钠/磷脂混合胶团可以成为CyA等难溶性多肽药物的一种新型增溶载体.     

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.     

Curcumin-loaded mixed micelles: preparation,optimization, physicochemical properties and cytotoxicity in vitro

Abstract

Although curcumin (CUR) can inhibit proliferation and induce apoptosis of tumors, the poor water solubility restricted its clinical application. The aim of this study was to improve the aqueous solubility of CUR and make more favorable changes to bioactivity by preparing curcumin-loaded phospholipid-sodium deoxycholate-mixed micelles (CUR-PC-SDC-MMs). CUR-PC-SDC-MMs were prepared by the thin-film dispersion method. Based on the results of single factor exploration, the preparation technology was optimized using the central composite design-response surface methodology with drug loading and entrapment efficiency (EE%) as indicators. The images of transmission electron microscopy showed that the optimized CUR-PC-SDC-MMs were spherical and well dispersed. The average size of the mixed micelles was 66.5?nm, the zeta potential was about ?26.96?mV and critical micelle concentration was 0.0087?g/l. CUR was encapsulated in PC-SDC-MMs with loading capacity of 13.12%, EE% of 87.58%, and the solubility of CUR in water was 3.14?mg/ml. The release results in vitro showed that the mixed micelles presented sustained release behavior compared to the propylene glycol solution of CUR. The IC₅₀ values of CUR-loaded micelles and free drug in human breast carcinoma cell lines were 4.10?μg/ml and 6.93?µg/ml, respectively. It could be concluded from the above results that the CUR-PC-SDC-MMs system might serve as a promising nanocarrier to improve the solubility and bioactivity of CUR.     

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...     

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。     

SDS-aided immobilization and controlled release of camptothecin from agarose hydrogel.

Camptothecin (CPT), known to be an effective anticancer drug, has a limited therapeutic utility because of its poor water solubility. In this work, an approach has been made to overcome the limitation. CPT was first incorporated into the micelles formed from an ionic surfactant, sodium dodecyl sulfate (SDS) and the micellar drug aqueous solution was then used in preparation of the agarose hydrogel. It has been found that the presence of SDS greatly increased the solubility of CPT in water. For example, in 1 ml of 1.0 wt.% SDS water solution, 0.11 mg CPT could be solubilized (0.318 mM), which was 83 times the solubility in pure water. It was the hydrophobic cores of the SDS micelles that were able to accept the lipophilic drug to form stable drug-immobilized micelles. The formulation of a hydrogel using the drug-immobilized micelles has allowed us to obtain a unique and novel drug release system where the drug molecules are encapsulated by the micelles and the drug-containing micelles are dispersed in the gel network. The release of CPT from the so deliberately fabricated agarose hydrogel system has been studied as a function of surfactant concentration at 37 degrees C. The diffusion coefficients of CPT obtained by fitting to Fick's law ranged from 2.12 to 7.36 x 10(-7)cm(2)s(-1). The results showed that SDS prolonged the drug release by reducing the diffusion coefficient of CPT in the gel.     

A polymeric micellar carrier for the solubilization of biphenyl dimethyl dicarboxylate

A polymeric micelle drug delivery system was developed to enhance the solubility of poorly-water soluble drug, biphenyl dimethyl dicarboxylate, DDB. The block copolymers consisting of poly(D,L-lactide) (PLA) as the hydrophobic segment and methoxy poly(ethylene glycol) (mPEG) as the hydrophilic segment were synthesized and characterized by NMR, DSC and MALDI-TOF mass spectroscopy. The size of the polymeric micelles measured by dynamic light scattering showed a narrow monodisperse size distribution with the average diameter less than 50 nm. The MW of mPEG-PLA, 3000 (MW of mPEG, 2 K; MW of PLA, 1 K), and the presence of hydrophilic and hydrophobic segments on the polymeric micelles were confirmed by MALDI-TOF mass spectroscopy and NMR, respectively. Polymeric micelle solutions of DDB were prepared by three different methods, i.e. the matrix method, emulsion method and dialy-sis method. In the matrix method, DDB solubility was reached to 13.29 mg/mL. The mPEG-PLA 2K-1 K micelle system was compared with the poloxamer 407 micelle system for their critical micelle concentration, micelle size, solubilizing capacity, stability in dilution and physical state. DDB loaded-polymeric micelles prepared by the matrix method showed a significantly increased aqueous solubility (>5000 fold over intrinsic solubility) and were found to be superior to the poloxamer 407 micelles as a drug carrier.     

替尼泊苷自微乳的处方筛选及体外评价

目的筛选替尼泊苷自微乳的最优处方,并对其进行体外评价。方法通过溶解度实验、伪三元相图的绘制、粒径考察筛选出最优处方;以替尼泊苷混悬液为对比,测定替尼泊苷自微乳在不同溶出介质中的溶出度;考察替尼泊苷自微乳的稳定性。结果实验筛选得到的最优处方为油酸乙酯∶Cremopher ELP∶异丙醇=20∶60∶20,载药量1.5%。在不同溶出介质中,替尼泊苷释药2h后的累积释药量均可达90%以上,且3h后的累积释药量接近100%。稳定性实验结果表明替尼泊苷自微乳在40℃、25℃和冷热循环条件下是稳定的。结论实验制得替尼泊苷自微乳具有较好的溶解度,在不同溶出介质中有较高溶出度,稳定性良好。     

Genistein-loaded poloxamer 403/407 mixed micelles: preparation and pharmacokinetic study in rats

In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein.Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated.In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were (20.31±0.43) nm and (–8.94±0.35) mV, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/mL, which was about 130 times higher than that in water.Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension.The AUC_0–t andAUC_0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively.Consequently,poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.     

Chirality plays critical roles in enhancing the aqueous solubility of nocathiacin I by block copolymer micelles

Objectives Although drug solubilization by block copolymer micelles has been extensively studied, the rationale behind the choice of appropriate block copolymer micelles for various poorly water‐soluble drugs has been of relatively less concern. The objective of this study was to use methoxy‐poly(ethylene glycol)‐polylactate micelles (MPEG‐PLA) to solubilize glycosylated antibiotic nocathiacin I and to compare the effects of chirality on the enhancement of aqueous solubility. Methods Nocathiacin I‐loaded MPEG‐PLA micelles with opposite optical property in PLA were synthesized and characterized. The drug release profile, micelle stability and preliminary safety properties of MPEG‐PLA micelles were evaluated. Meanwhile, three other poorly water‐soluble chiral compound‐loaded micelles were also prepared and compared. Key findings The aqueous solubility of nocathiacin I was greatly enhanced by both l ‐ and d ‐copolymers, with the degree of enhancement appearing to depend on the chirality of the copolymers. Comparison of different chiral compounds confirmed the trend that aqueous solubility of chiral compounds can be more effectively enhanced by block copolymer micelles with specific stereochemical configuration. Conclusions The present study introduced chiral concept on the selection and preparation of block copolymer micelles for the enhancement of aqueous solubility of poorly water‐soluble drugs.     

壳聚糖衍生物及其胶束：特性、功能化修饰和在药物传递系统中的应用

壳聚糖是一种天然多糖,具有无毒、可生物降解、生物相容性等诸多优点,但水溶性差的自身特点限制了其在药剂学中的应用,而其经合理的结构设计、修饰和优化,可获得性能良好的两亲性壳聚糖衍生物,这些衍生物在水溶液中能自组装成具有良好药物传输性能（如载药量、稳定性、刺激敏感性、靶向性等）的胶束,并被广泛应用于构建药物传递系统,以改善药物的溶解性、靶向性、生物利用度及耐药性．降低药物的毒副作用。综述壳聚糖衍生物结构对其胶束药物传输性能的影响以及壳聚糖衍生物及其胶束的功能化修饰和在药物传递系统中的应用。     

微载体药物递送系统在姜黄素中的应用研究进展

目的综述微载体药物递送系统在姜黄素中的应用研究进展,进一步了解姜黄素的研究概况。方法分别介绍姜黄素的纳米粒、微球、微乳、微囊、胶束、脂质体、磷脂复合物、环糊精包合物等递送系统的研究进展。结果微载体药物递送系统被广泛的应用于提高姜黄素的溶解度和稳定性,进而提高药物在体内的生物利用度。结论微载体药物递送系统在姜黄素中的应用研究为姜黄素进一步应用于临床提供研究基础。     

丙泊酚mPEG-PLA/普朗尼克混合胶束的制备和性质(英文)

采用生物相容性聚合物胶束材料聚乙二醇-聚乳酸(mPEG-PLA)和普朗尼克P105(P105),构建了全新的混合胶束体系,用于提高难溶性麻醉药—丙泊酚的溶解度。相对于单纯由mPEG-PLA构建的载药胶束,该载药混合胶束能有效提高药物溶解度。最优化处方为mPEG-PLA:P105:丙泊酚=10:4:5(w/w/w),粒径约为90nm,多分散指数为0.2左右。载药混合胶束中游离药物浓度显著低于市售品脂肪乳(P<0.05)。此混合胶束于4oC条件下放置6个月,其粒径、多分散指数、游离药物浓度和载药量均无明显变化,说明4oC条件下该体系在6个月内是稳定的。混合胶束在各时间点的体外释放百分率显著高于市售品脂肪乳,这可能有利于更快发挥药效。睡眠/苏醒试验结果表明,混合胶束、单一胶束以及市售品脂肪乳的翻正反射消失时间和恢复时间没有显著性差异(P>0.05)。上述结果表明该混合胶束有望成为静脉给药系统应用于临床。     

环孢素A混合胶束的制备与理化性质考察

目的制备环孢素A混合胶束并对其理化性质进行研究。方法通过正交设计筛选环孢素A混合胶束的最佳处方,并考察其形态、粒径、Zeta电位、载药量、包封率和体外释放情况。结果最佳处方为环孢素A与磷脂的质量比为1∶7、胆固醇硫酸酯钠与磷脂的质量比为1∶4、水合介质为双蒸水,由此制备出的胶束呈球形,平均粒径为(139.2±2.3)nm,Zeta电位为(-25.3±0.56)mV,胶束的载药量达(6.04±0.04)g/L,包封率为(94.5±0.46)%,24 h内体外累积释放(33.1±2.7)%。结论用优化处方制备的环孢素A混合胶束,其稳定性和分散性良好,具有一定缓释作用。     

Solubilization of Drugs by Physiological Mixtures of Bile Salts

Purpose. The solubilization of a number of steroids was determined in bile salt simple micelles and a bile salt/phospholipid micellar system to provide a better basis to predict the extent of drug solubilization in vivo. Methods. Excess solid drug was dispersed in taurodeoxycholate or mixed micelle solutions prepared with fixed mole ratios of taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycodeoxycholate, glycocholate, and glycochenodeoxycholate with egg phosphatidylcholine. Drug concentrations were determined from the absorbance following centrifugation. Using NMR spectroscopy, the diffusivities of the simple and mixed micelles were 2 × 10^-6 and 8 × 10^-7 cm²/s, respectively. Results. From the change in the concentration of drug in solution with a change in the lipid concentration, the solubilization ratio (SR) was calculated. The SR and aqueous solubility were used to calculate the micelle/aqueous partition coefficients (K_m/w). K_m/w was correlated with octanol/water partition (P_o/w) for the TDC and mixed micelle data sets with correlation lines of logK_m/w = 0.74logP_o/w + 1.55 (r² = 0.91) and logK_m/w = 0.61 logP_o/w + 2.44 (r² = 0.95), respectively. Conclusions. With such data, a refined, predictive relationship between the in vitro and the in vivo solubilization with additional information concerning the bile salt/lipid concentration in the human intestine appears possible.     

What Is the Mechanism Behind Increased Permeation Rate of a Poorly Soluble Drug from Aqueous Dispersions of an Amorphous Solid Dispersion?

Our aim was to explore the influence of micelles and microparticles emerging in aqueous dispersions of amorphous solid dispersions (ASDs) on molecular/apparent solubility and Caco-2 permeation. The ASD, prepared by hot-melt extrusion, contained the poorly soluble model drug ABT-102, a hydrophilic polymer, and three surfactants. Aqueous dispersions of the ASD were investigated at two concentrations, one above and one close to the critical micelle concentration of the surfactants blend in the extrudate. Micelles were detected at the higher concentration and no micelles at the lower concentration. Apparent solubility of ABT-102 was 20-fold higher in concentrated than in diluted dispersions, because of micelles. In contrast, Caco-2 permeation of ABT-102 was independent of the ASD concentration, but three times faster than that of crystalline suspensions. Molecular solubility of ABT-102 (equilibrium dialysis) was also independent of the ASD concentration, but by a factor 2 higher than crystalline ABT-102. The total amount of ABT-102 accumulated in the acceptor during Caco-2 experiments exceeded the initial amount of molecularly dissolved drug in the donor. This may indicate that dissolution of amorphous microparticles present in aqueous dispersions induces lasting supersaturation maintaining enhanced permeation. The hypothesis is supported by a slower drug permeation when the microparticles were removed. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:1779–1786, 2014     

Preparation and evaluation of icariside II-loaded binary mixed micelles using Solutol HS15 and Pluronic F127 as carriers

An effective anti-cancer drug, icariside II (IS), has been used to treat a variety of cancers in vitro. However, its poor aqueous solubility and permeability lead to low oral bioavailability. The aim of this work was to use Solutol®HS15 and Pluronic F127 as surfactants to develop novel mixed micelles to enhance the oral bioavailability of IS by improving permeability and inhibiting efflux. The IS-loaded mixed micelles were prepared using the method of ethanol thin-film hydration. The physicochemical properties, dissolution property, oral bioavailability of the male SD rats, permeability and efflux of Caco-2 transport models, and gastrointestinal safety of the mixed micelles were evaluated. The optimized IS-loaded mixed micelles showed that at 4:1 ratio of Solutol®HS15 and Pluronic F127, the particle size was 12.88?nm with an acceptable polydispersity index of 0.172. Entrapment efficiency (94.6%) and drug loading (9.7%) contributed to the high solubility (11.7?mg/mL in water) of IS, which increased about 900-fold. The SF-IS mixed micelle release profile showed a better sustained release property than that of IS. In Caco-2 cell monolayer models, the efflux ratio dramatically decreased by 83.5%, and the relative bioavailability of the mixed micelles (AUC_0–∞) compared with that of IS (AUC_0–∞) was 317%, indicating potential for clinical application. In addition, a gastrointestinal safety assay also provided reliable clinical evidence for the safe use of this micelle.     

Amphiphilic block copolymers-based mixed micelles for noninvasive drug delivery

Amphiphilic block copolymers-based mixed micelles established as new drug-loading system showed superior characteristics in delivering drug such as improved solubility, enhanced stability, multifunctional carrier materials, targeting ability, and high bioavailability. Recently, there are increasing focuses on exploration and study of noninvasive routes, and the results present perfect feasibility, improved compliance and fewer aches and pains. The aim to apply mixed micelles to noninvasive alternative routes has driven massive pharmaceutical attention. Recently, various studies of micelles strategy for noninvasive routes have been conducted to overcome the inherent barriers for uptake across the gastrointestinal tract, mucosal membranes and other in vivo noninvasive barriers, and the result argues well. The objective of this article is to summary these studies and developments of mixed micelles used on noninvasive drug delivery and provide a reference for further research.