淀粉乳液形成过程主要影响因素的耗散粒子动力学模拟与实验

以环己烷为油相、淀粉乳液为水相、Span60和Tween60为乳化剂, 用耗散粒子动力学(DPD)方法研究了淀粉乳液形成过程及油水比、乳化剂用量等因素对淀粉乳液形成的影响. 结果表明, 模拟6000步时, 体系达到平衡状态; 乳滴的粒径随乳化剂含量的增加先减小而后增加, 随淀粉含量的增加而增加, 随环己烷含量的减小而增加; 形成稳定淀粉乳液体系的参数范围: 7＜油水比≤20, 9%＜乳化剂用量≤18%. 实验结果表明, 乳化剂含量为11%～15%时, 微球的粒径随乳化剂含量的增大而减小; 乳化剂含量大于15%时, 微球的粒径反而增大. 实验与模拟的结果吻合.     

微乳体系相图及其在液相色谱分离多组分药物应用的研究

采用滴加法和电导率法绘制了十二烷基硫酸钠(SDS)/正丁醇/油相(正辛醇、正辛烷、正庚烷、正己烷)/水四组分微乳体系的拟三元相图。以O/W型微乳区域大小为指标,考察不同油相、表面活性剂与助表面活性剂的质量比对微乳形成的影响,并通过测定电导率、相对粘度以及表面张力等物理化学参数,考察了微乳体系的相行为及特性。根据得到的微乳体系相图,进行色谱条件优化,建立了快速、稳定的测定阿莫西林舒巴坦匹酯片剂中阿莫西林与舒巴坦匹酯二组分含量的方法,结果显示此微乳分离系统有较好的色谱适用性及方法可行性。     

钙离子通道阻滞剂自乳化给药系统的形成机理

以一系列难溶性的二氢吡啶类钙离子通道阻滞剂作为模型药物,以自乳化面积和药物在自乳化给药系统(SEDDS)中的溶解度作为自乳化评价指标,建立各组分的分子描述参数与自乳化性质之间的定量函数关系,通过模型讨论分子结构对自乳化形成机理的影响.结果表明,自乳化的发生是各组分含量、分子间作用力、亲脂性和分子大小等多方面因素综合作用的结果.当混合表面活性剂分子较大且药物脂溶性较好时,SEDDS对难溶性药物的增溶能力较强;表面活性剂与助表面活性剂的质量比较大,混合表面活性剂的分子较大时,SEDDS的稀释稳定性较好.     

磁场对苯胺微乳液聚合体系相行为的影响

通过十二烷基苯磺酸钠(SDBS)/正丁醇(n-butanol)/苯胺/水微乳液体系的拟三元相图,考察了恒定磁场(0.4T)和助表面活性剂与表面活性剂的质量比(Km=mn-butanol/mSDBS)对苯胺微乳液聚合体系的相行为、电导行为以及微乳化作用的影响.结果表明:随着体系醇含量的增加,微乳区面积先增大后减小,当Km值为1.0时,形成的微乳区最大;外加磁场可以增大微乳区面积.通过对外加磁场条件下溶液电导率随水含量变化规律的分析,印证了拟三元相图的表征结果.透射电镜分析结果表明,磁场条件下合成的聚苯胺颗粒比无磁场条件下合成的聚苯胺颗粒小.     

Tween80/BmimPF6/醇/甲苯体系的相行为

以环境友好型的Tween80为表而活性剂,以醇(乙醇、正丁醇、正己醇、正辛醇、正癸醇和异戊醇)为助表面活性剂,对离子液体1-丁基-3-甲基咪唑六氟磷酸盐(bmimPF6)和甲苯进行了微乳化实验,绘制了不同条件下Tween80离子液体的微乳体系的拟二元相图,考察了醇的种类、含量对单相微乳区的影响,并用电导法研究了在乙醇为助表面活性剂情况下,单相微乳区的结构转变.结果表明,当醇(异戊醇)固定时,随着表面活性剂/醇的质量比增加,单相微乳区的面积逐渐增大:不同链长的直链醇对单相微乳区的而积影响与该醇在离子液体中的溶解情况有关,单相微乳区的面积随着直链醇链长的增加而越小;当乙醇作助表面活性剂时,所得到的单相微乳区的而积最大,且单相微乳区存在着O/IL(oil-in-ionic liquid)、双连续相和IL/O(ionic liquid-in-oil)三种微结构.尤其对离子液体微乳体系的电导随油的含量的增加而最初增大的现象进行了解释,这一现象是由于油主要起到减少离子液体中离子对或离子的积聚,提高带电离子淌度的作用.     

Tween80/BmimPF6/醇/甲苯体系的相行为

以环境友好型的Tween80为表面活性剂, 以醇(乙醇、正丁醇、正己醇、正辛醇、正癸醇和异戊醇)为助表面活性剂, 对离子液体1-丁基-3-甲基咪唑六氟磷酸盐(bmimPF6)和甲苯进行了微乳化实验, 绘制了不同条件下Tween80离子液体的微乳体系的拟三元相图, 考察了醇的种类、含量对单相微乳区的影响, 并用电导法研究了在乙醇为助表面活性剂情况下, 单相微乳区的结构转变. 结果表明, 当醇(异戊醇)固定时, 随着表面活性剂/醇的质量比增加, 单相微乳区的面积逐渐增大; 不同链长的直链醇对单相微乳区的面积影响与该醇在离子液体中的溶解情况有关, 单相微乳区的面积随着直链醇链长的增加而越小; 当乙醇作助表面活性剂时, 所得到的单相微乳区的面积最大, 且单相微乳区存在着O/IL(oil-in-ionic liquid)、双连续相和IL/O(ionic liquid-in-oil)三种微结构. 尤其对离子液体微乳体系的电导随油的含量的增加而最初增大的现象进行了解释, 这一现象是由于油主要起到减少离子液体中离子对或离子的积聚, 提高带电离子淌度的作用.     

明胶微球粒径控制的研究

采用乳化-凝聚法,在油包水(w/o)的体系中对明胶微球(GMs)粒径、微球的形态和分散性等进行了研究.扫描电子显微镜(SEM)和粒径分布曲线的结果表明在乳化体系中,提高明胶溶液的浓度或水油比例,明胶微球的粒径增大;增加乳化剂的用量,微球的粒径减小;选择合适的乳化时间和搅拌速率,可以改善微球的分散性和表面光滑程度.同时,通过调控实验条件,在明胶溶液浓度0.100 g/mL,水油比1/5,乳化剂浓度0.05g/mL时研制出了平均粒径为3.58μm的表面光滑、分散性好的明胶微球.     

双重乳液/溶剂蒸发法制备超声造影微泡

通过水包油包水(W1/O/W2)双重乳液的油相溶剂蒸发过程, 制备了聚左旋乳酸(PLLA)微泡, 结合扫描电子显微镜(SEM)、激光共聚焦显微镜(LCSM)和粒度分析(PSA)等表征手段, 研究了外水相乳化剂的种类、浓度、两次乳化的水油比、均质机转速等参数对微泡性能的影响. 研究结果表明, 聚乙烯醇(PVA)是该体系外水相有效的乳化剂; 通过调节PVA水溶液的浓度或第二次乳化时均质机转速, 能有效地控制微泡的平均粒径(1~10 μm); 第一次乳化的水油比是微泡空心率的重要影响因素. 对微泡负压充气后, 进行体外超声显影检测, 证明该微泡具有较好的超声造影增强效果.     

磁场对复配乳化剂/苯胺微乳液聚合体系相行为的影响

首次在酸性条件下, 以十二烷基苯磺酸钠(SDBS)和聚乙二醇辛基苯基醚(TX-100)为复配乳化剂, 制备SDBS/TX-100/正丁醇(nBA)/苯胺(An)/盐酸(HCl)微乳液体系, 并通过该体系的拟三元相图, 考察了恒定磁场(0.4 T)、助表面活性剂(nBA)与复配乳化剂的质量比(K_m＝m_nBA/m_SDBS/TX-100)及SDBS与TX-100的质量比(S_m＝m_SDBS/m_TX-100)对复配乳化剂/苯胺微乳液聚合体系相行为和电导行为的影响. 结果表明: 随着K_m的增加, 微乳区面积先增大后减小, 当K_m＝1.0时, 形成的微乳区面积最大|随着S_m的减少, 微乳区面积逐渐增大|外加磁场可以增大微乳区面积, 且随着S_m的减小, 磁场对微乳液体系的作用逐渐减弱. 循环伏安的测试结果表明, 复合乳化剂微乳液法制备的聚苯胺, 其循环伏安性能优于单组分乳化剂(SDBS或TX-100)微乳液法制备的聚苯胺.     

生物质快速热解油水相溶液超声乳化特性

使用生物油水相溶液与0# 柴油乳化,筛选了四种常用乳化剂和一种助乳化剂进行复配乳化实验,考察了复配乳化剂型号、乳化剂用量、超声作用时间对乳化效果的影响。结果表明,六种乳化液超过30d不破乳,与0# 柴油相比,密度和热值相差不大,含水量3%以下,黏度增大约40%,pH值降低一半。因素分析法表明,水相溶液与柴油质量比和不同的水相溶液对乳化效果影响较大。探讨了乳化机理,认为生物油水相溶液中水、醛、酸、酮等极性组分化合物稳定地被乳化剂包裹在W/O型乳化液液滴中,生物油水相溶液中少量的乙酸乙酯、芳香类化合物等则增溶于非离子乳化剂胶束中。热力学分析表明,超声乳化作用比静置作用具有更大的熵增,乳化液更趋于稳定平衡状态。     

New catanionic surfactants, phase stability and synthesis of ultrafine CdS nanoparticles

A systematic study on the water-intake capacity of the microemulsion formed using a catanionic surfactant (synthesized by taking equimolar mixture of acid and amine) with varying hydrocarbon chain length of the acid has been carried out. A decrease in the water-intake capacity with increase in the chain length was observed. Shorter chain length of co-surfactant (1-butanol compared to 1-octanol) led to higher water-intake capacity of microemulsions which may also be attributed to the high hydrophilic-lipophilic balance (HLB) of 1-butanol. Three new microemulsions based on catanionic surfactants have been used to synthesize quantum dots of CdS. The size of CdS quantum dots decreased with increase in chain length of the acid component of the catanionic surfactant.     

油酸单乙醇酰胺聚氧乙烯醚微乳液体系的研究

以油酸单乙醇酰胺聚氧乙烯醚作为乳化剂制备水包油型微乳液.通过拟三元相图、粒径大小及粒径分布确定较优配方:复配表面活性剂(由油酸单乙醇酰胺聚氧乙烯醚和吐温20组成)的亲水亲油平衡值(HLB值)为15,助表面活性剂为正丁醇,复配表面活性剂与助表面活性剂的质量比(Km值)为1,混合表面活性剂与正辛烷的质量比(S/O值)=1∶...     

Thermoanalytical investigation of lyotropic liquid crystals and microemulsions for pharmaceutical use

The interactions between surfactant and water were studied thermoanalytically focusing on the lyotropic liquid crystalline and microemulsion region in four ternary systems containing Cremophor EL and Cremophor RH40 as surfactants, neutral oil and isopropyl myristate as oily components. Subzero temperature DSC (SZT-DSC) measurements were carried out to determine the quantity of the bound water forming a hydration layer in surfactant microstructures, and the amount of free water, which has physico-chemical properties not much different from those of pure water. The variation of the surfactant:bound water ratio in the function of water concentration was also investigated. Phase changes detected by the SZT-DSC measurements were confirmed by polarization-microscopic and rheological investigations.     

微乳毛细管电动色谱微乳粒径电化学测定方法研究

以二茂铁(Fc)作为电化学探针,采用循环伏安法测定了微乳毛细管电动色谱中常用水包油型微乳体系十二烷基硫酸钠(SDS)/正丁醇/正辛烷在不同配比下的扩散系数,并通过扩散系数推算微乳粒径的变化规律。研究表明,随着表面活性剂SDS浓度增加,粒径减小;随着正丁醇的增加,粒径减小;正辛烷的量对粒径影响不大。使用动态激光光散射法对实验结果进行验证,发现当电活性物质Fc全部溶于油相中时,两种方法测定结果基本相符;但随着正丁醇浓度增大,粒径是增大的。Fc在微乳液滴油核外的溶解度增大,导致测量误差增大。     

Determination of phthalate esters in soil by microemulsion electrokinetic chromatography coupled with accelerated solvent extraction

A novel method using microemulsion electrokinetic chromatography combining accelerated solvent extraction was developed for quantitative analysis of six phthalate esters (PAEs) including dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, as well as dioctyl phthalate. The effect of each individual component within the microemulsions, i.e. oil phase, surfactant and co-surfactant on resolution of the analytes was systematically studied. Baseline separation of six PAEs was achieved within 26?min by using the microemulsion buffer containing a 60?mmol/L borate buffer at pH 9.0, 0.5% v/v n-octane as oil droplets, 100?mmol/L sodium cholate as surfactant and 5.0% v/v 1-butanol as co-surfactant. The purposed accelerated solvent extraction-microemulsion electrokinetic chromatography method was successfully applied to the determination of trace amount of PAEs in soil samples collected from three different fields in areas of Fujian Province and the contents of dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate and dioctyl phthalate were 0.63-0.68, 0.32-0.63, 2.53-3.96, 0-1.75, 7.32-11.7 and 0-3.46mg/kg, respectively. It was validated that the results were consistent with those obtained by GC-MS method.     

Paliperidone-Loaded Self-Emulsifying Drug Delivery Systems (SEDDS) for Improved Oral Delivery

The present research is aimed to improve the oral delivery of paliperidone by loading into self-emulsifying drug delivery systems (SEDDS). Oleic acid, Tween 80, and capmul MCM L8 were selected as oil, surfactant, and co-surfactant, respectively and phase diagram was constructed and the region was identified for the formation of SEDDS. The stable formulations were analyzed for globule size, robustness to dilution and in vitro drug release. The globule size of all the formulations was found to be in the range of 205 to 310 nm with good size uniformity and seems to be dependent on the proportion of oil in SEEDS formulation. The optimized formulation (F3) has been adsorbed onto neusilin and characterized. The DSC and XRD spectra unravel the presence of molecular state of paliperidone in solid SEDDS. The in vitro dissolution study indicates improved dissolution characteristics with higher dissolution efficiency for solid SEDDS (SEDDS-N) compared to pure drug. Further ex vivo permeation studies carried out using rat intestine suggest a 2- to 3-fold improvement in permeation for SEDDS compared to pure drug. In conclusion, SEDDS prove to be potential carriers for improved oral delivery of paliperidone.     

A new and simple method for sulfur nanoparticles synthesis

Sulfur nanoparticles were successfully synthesized via novel water-in-oil microemulsion system. The microemulsion system contained cyclohexane as an oil phase, Triton X-100 as a surfactant, butanol as a co-surfactant and sodium polysulfide solution or hydrochloric acid solution as aqueous phase, respectively. The sulfur nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. The results showed that the as-prepared monoclinic sulfur nanoparticles exhibited high purity and spherical shape with an average size of about 22 nm.     

Gel dispersed liquid crystals

Microemulsion based gels (MBG) can be used as carrier materials for dispersed thermotropic liquid crystals (LC). The viscosity of the carrier material can be specifically changed by varying the gelatin content. The LC droplet sizes and their distribution in the MBG system are influenced by both the ratio between AOT surfactant and alcohol co-surfactant and the length of the carbon chain of the co-surfactant. LC droplets without or with only a small amount of alcohol co-surfactant have the same droplet size and show a radial structure.     

Comparison of O/W and IL/W Microemulsion Systems as Potential Carriers of Sparingly Soluble Celecoxib Drug

Active pharmaceutical ingredients with poor solubility in water and some organic solvents are a challenge in the pharmaceutical industry. To overcome this limitation, microemulsion systems are a choice to increase the solubility of a sparingly soluble active ingredient. The purpose of this study is to introduce and compare two types of oil-in-water (O/W) and ionic liquid-in-water (IL/W) microemulsions, which were formulated to increase the solubility of celecoxib as an active pharmaceutical ingredient. The proposed formulations are composed of the same nonionic surfactant/co-surfactant of Tween-80/transcutol®P, and different oil phases of isopropyl myristate, [BMIM][PF6] and [OMIM][PF6]. The pseudo-ternary phase diagrams for the microemulsion systems have been determined at a surfactant-to-co-surfactant mass ratio of 3:1 and 298.15 K. From the microemulsion region of the phase diagrams, four formulations was selected and their physico-chemical properties as density, viscosity, refractive index, electrical conductivity and surface tension were measured at 298.15 K. The solubilities of celecoxib in all selected formulations were also determined and compared. The results show considerable increases in solubility of the celecoxib in the ionic liquid-based microemulsion systems.