利用SPG膜制备O/W型乳液实验研究

利用孔径为0.6μm的SPG(Shirasu Porous Glass)多孔微滤膜,以异辛烷为分散相、pH=7的磷酸盐缓冲水溶液为连续相、以SDS(十二烷基硫酸钠)和PVA(聚乙烯醇)分别为水相乳化剂和稳定剂,制备了O/W型乳液,研究了操作条件对乳液性能包括液滴大小及分布的影响关系.当跨膜压差在0.12~0.16 MPa时,连续相流速分布在0.20~0.40 m/s时,乳化剂浓度在其临界胶束浓度(CMC)之上时,乳液的单分散性较好.由于乳液具有良好的稳定性和单分散性,可用于多相界面酶催化反应.     

核孔膜乳化法制备单分散壳聚糖微球

选择壳聚糖溶液为分散相,液体石蜡为连续相,首次采用核孔膜乳化方法制备壳聚糖微球.乳滴经戊二醛交联固化后所得微球球形度和单分散性良好(分散系数＜20%).主要研究了核孔膜孔径大小、油水相体积比、表面活性剂种类及用量、温度和固化时间对微球制备的影响.结果表明,膜乳化法是制备单分散微球的良好方法.     

共轴微通道水相微球制备

本文以竖直共轴微通道为研究对象,采用去离子水为分散相、5W-20润滑油为连续相,二者在微通道内形成两相流,在管外收集到单分散水相微球,分散相流量Qd的变化范围6ml/h~84ml/h,连续相流量Qc的变化范围6ml/h~192ml/h。发现在以连续相流量Qc为横坐标、分散相流量Qd为纵坐标的水相微球直径图中,单分散水相微球的形成区域存在一条穹顶形边界。单分散的水相微球分布在此边界下部,随着连续相流量Qc的增加,单分散水相微球的形成边界呈现出先上升后下降的趋势。形成单分散水相微球的Qd60ml/h。单分散水相微球直径与两相流量比(Qd/Qc)呈现出对数增加的关系。     

膜乳化过程研究进展

简要综述了膜乳化过程的机理、操作参数的影响和乳液性质等.操作参数包括膜材料、膜孔径及孔隙率、连续相速率、跨膜压差、乳化剂等.通过控制合适的操作参数,可制备出具有所需尺寸的单分散乳液.     

聚亚胺类物质在抗温(w1/o)/w2多重乳液中的应用研究

多重乳液的热稳定性是应用于石油工程等领域的关键.以聚氧乙烯失水山梨醇单月桂酸酯(T20)为亲水乳化剂,通过微观界面性质及宏观稳定性实验研究了聚异丁烯丁二酰亚胺(T161)为亲油乳化剂时多重乳液的热稳定性,借助界面吸附状态的研究对其热稳定机理进行了分析.同时对比了失水山梨醇单油酸酯(S80)为亲油乳化剂时多重乳液的相应性能.研究表明70℃条件下聚亚胺类物质制备的多重乳液30天后破裂率低于25%,具有良好的热稳定.原因在于其高的界面吸附平衡常数(93.4m3/mol)与单位摩尔乳化剂占据的界面面积(1.92×106m2/mol).研究结果为多重乳液应用领域拓展奠定了基础.     

液液两相流法制备海藻酸钠包覆的液态金属微滴

本文以室温液态金属(GaInSn)为分散相、海藻酸钠(NaAlg)溶液(1wt%)为连续相,采用液液两相流方法,在竖直共轴微通道中,制备得到NaAlg凝胶包覆的多个GaInSn微滴,具有单分散、尺寸一致的特点。GaInSn/NaAlg两相流存在四种流型:分散相滴流、分散相柱塞流、连续相滴流和连续相射流。GaInSn微滴的包覆模式三种:Squeezing、Dripping和Compound Jetting,其中Dripping和Compound Jetting是主要的包覆模式。在较低的GaInSn流量下,NaAlg流量增加到一定程度后,包覆模式由Dripping转变Compound Jetting。固定两相流量比,随着两相流量的同比例增加,GaInSn微滴的特征频率呈线性增加、包覆个数增加、特征长度变化不显著。     

聚合物异形粒子的制备与形态表征及应用

通过浓乳液的方法制备了系列聚苯乙烯异形粒子.浓乳液体系的分散相体积分数最高到94.7%,并且在分散相中加入交联剂二乙烯基苯（DVB）以固定粒子形态.聚合后所得粒子通过透射电子显微镜观察其形态,用圆度公式表征了不同配方所得粒子的异形程度,讨论了分散相体积分数、交联剂含量对聚苯乙烯异形粒子形态的影响.此外,对不同异形度的粒子增韧酚醛树脂的研究表明,粒子异形度越高,增韧效果越好。     

熔体的粘性和弹性对LDPE／PS共混物形态的影响

研究了粘性和弹性对低密度聚乙烯／聚苯乙烯共混物形态的影响。结果表明，不相容聚合物在均匀剪切流动中的分散程度以及分散相的形状与组分的粘度比、相对弹性和体积分数有关。当分散相的粘性和弹性较基相大得多时，随分散相的体积分数增加，球状的液滴形成葡萄串状。若两组分的粘性和弹性相当，在适中的混合比下，分散相产生高度变形。不管组分的粘反比和弹性比大小，若分散相的体积分数非常低，共混物的主要形态皆为分散相的球状液滴分散在基体中。     

尼龙6/聚苯乙烯共混物融合缝的形态及其对力学性能的影响

采用扫描电镜(SEM)、力学性能测定,研究了尼龙6／聚苯乙烯(PA-6／PS)共混体系融合缝的形态及力学性能．鲒果表明,分散相和连续相的粘度比对融合缝的形态有重要影响．当η分散相／η连续相＞1时,融合缝处分散相的形态不同于本体．融合缝处分散相沿融合缝取向;当η分散相／η连续相＜1时．融合缝处分散相的形态与本体形态相似．均以球形粒子分散于基体中。融合缝的存在使共混体系的力学性能有较大下降,主要由融合缝处分散相形态所致。     

聚苯乙烯/二乙烯基苯多孔材料的制备工艺研究

以高内相比乳液模板法制备了PS/DVB(聚苯乙烯/二乙烯基苯)多孔材料,研究了连续相的性质、致孔剂和乳化剂对PS/DVB多孔材料表面结构的影响.结果表明,连续相疏水性的提高有助于提高乳液的稳定性,致孔剂与PS之间良好的相容性有利于提高多孔材料的比表面积;复合乳化体系更能有效地降低乳液的界面张力,增加多孔材料的比表面积.     

The effect of poloxamer viscosity on liquid-filling of solid dispersions in hard gelatin capsules

Preliminary studies were undertaken on poloxamers to investigate their suitability for liquid-fill formulations for hard gelatin capsules. Poloxamers with viscosity in the range (0.32-2.8 Pa s) and melting point 48-58 degrees C were used as the continuous phase, with alpha-lactose monohydrate of negligible solubility in the molten poloxamers, as a model insoluble disperse phase. Physicochemical characterization by rheology, melt solidification and moisture uptake indicated that poloxamers were suitable excipients for liquid-filling in hard gelatin capsules. 10% w/w lactose/poloxamer dispersions were thixotropic and shear thinning and exhibited good capsule-filling properties, disperse-phase uniformity and satisfactory apparent viscosity at 70 degrees C.     

乳状液制备新工艺——膜乳化过程实验研究

用膜乳化系统制备了Ｏ／Ｗ型乳状液,考察了乳化时间、平均膜孔径、壁面剪应力、膜两侧压差和乳化剂等因素对乳化效果的影响．实验显示,分散相液滴平均直径不随乳化时间而变化;在此条件下,该直径约是膜平均孔径的５～１２倍．随着连续相一侧壁面剪应力的增大液滴平均直径减小,但当壁面剪应力大到一定值后,减小的幅度变得很小．增大膜平均孔径和膜两侧压差都将增加分散相透过膜的通量．此外,乳化剂分子的吸附速度越快,分散相液滴平均直径越小．     

The Effect of Poloxamer Viscosity on Liquid-Filling of Solid Dispersions in Hard Gelatin Capsules

ABSTRACT

Preliminary studies were undertaken on poloxamers to investigate their suitability for liquid-fill formulations for hard gelatin capsules. Poloxamers with viscosity in the range (0.32–2.8 Pa s) and melting point 48–58°C were used as the continuous phase, with α-lactose monohydrate of negligible solubility in the molten poloxamers, as a model insoluble disperse phase. Physicochemical characterization by rheology, melt solidification and moisture uptake indicated that poloxamers were suitable excipients for liquid-filling in hard gelatin capsules. 10% w/w lactose/poloxamer dispersions were thixotropic and shear thinning and exhibited good capsule-filling properties, disperse-phase uniformity and satisfactory apparent viscosity at 70°C.     

Effect of Dextrose in the Internal Aqueous Phase on Formation and Stabiblity of W/O/W Multiple Emulsions

The osmolarity of the internal aqueous phase of W/O/W multiple emulsions was varied by using different concentrations of dextrose in the internal phase. Evaluation of the stability of the emulsions was done by microscopic, viscometric and conductometric methods. Microscopic study indicated that as the dextrose concentration in the internal phase increased (0 - 2.50% W/V), the stability, in terms of coalescence of the internal droplets and rupture of the interfacial oily layer, increased from 12 hrs to 7-8 weeks. Viscometric evaluation showed the emulsions to exhibit Non-Newtonian flow and the apparent viscosities of freshly prepared emulsions increased from 8000 to 56,000 cps as the dextrose concentration was increased; the viscosity decreased as the emulsion aged. The amount of drug released as determined by the conductometric method, correlated with the viscosity and stability of the emulsions. The reduction of globule size of the primary (W/O) phase by use of a colloid mill increased the apparent viscosity significantly and thus improved the stability of the formulations.     

Effect of Dextrose in the Internal Aqueous Phase on Formation and Stabiblity of W/O/W Multiple Emulsions

Abstract

The osmolarity of the internal aqueous phase of W/O/W multiple emulsions was varied by using different concentrations of dextrose in the internal phase. Evaluation of the stability of the emulsions was done by microscopic, viscometric and conductometric methods. Microscopic study indicated that as the dextrose concentration in the internal phase increased (0 – 2.50% W/V), the stability, in terms of coalescence of the internal droplets and rupture of the interfacial oily layer, increased from 12 hrs to 7-8 weeks. Viscometric evaluation showed the emulsions to exhibit Non-Newtonian flow and the apparent viscosities of freshly prepared emulsions increased from 8000 to 56,000 cps as the dextrose concentration was increased; the viscosity decreased as the emulsion aged. The amount of drug released as determined by the conductometric method, correlated with the viscosity and stability of the emulsions. The reduction of globule size of the primary (W/O) phase by use of a colloid mill increased the apparent viscosity significantly and thus improved the stability of the formulations.     

Stability study of W/O/W viscosified multiple emulsions

Stable multiple emulsions with a small proportion of primary emulsion containing different viscosifying agents in the outer aqueous phase were formulated. The multiple systems were assessed by evaluating several parameters, such as the macroscopic aspect, droplet size, release rate, and accelerated stability under elevated temperatures. The effect of different viscosifying agents at different concentrations on the stability and the multiplicity of the multiple emulsions was examined. The viscosity increased by increasing the concentration of the viscosifying agents. It also appeared that the viscosifying agents increased the temperature stability of the multiple emulsions. As a result, the formulation viscosified with Klucel was more stable, while the one prepared with carbomer viscosified the outer phase at much lower concentrations with much better skin feel.     

Stability Study of W/O/W Viscosified Multiple Emulsions

Stable multiple emulsions with a small proportion of primary emulsion containing different viscosifying agents in the outer aqueous phase were formulated. The multiple systems were assessed by evaluating several parameters, such as the macroscopic aspect, droplet size, release rate, and accelerated stability under elevated temperatures. The effect of different viscosifying agents at different concentrations on the stability and the multiplicity of the multiple emulsions was examined. The viscosity increased by increasing the concentration of the viscosifying agents. It also appeared that the viscosifying agents increased the temperature stability of the multiple emulsions. As a result, the formulation viscosified with Klucel was more stable, while the one prepared with carbomer viscosified the outer phase at much lower concentrations with much better skin feel.     

Rheology and Filling Characteristics of Particulate Dispersions in Polymer Melt Formulations for Liquid Fill Hard Gelatin Capsules

Abstract

The rheology and capsule filling properties of molten excipients, Dynafill, Dynasan-114, Lutrol-F68, and polyethylene glycols (PEG) 6000, 8000, 10,000, and 20,000 have been investigated. Lactose (α-monohydrate) was selected as a model particulate solid with low solubility in PEG in order to investigate the effects of disperse phase particle size, concentration, and PEG molecular weight on rheology and capsule filling properties of these systems. All excipients behaved as Newtonian fluids between 65 and 90°C, which was chosen as a possible temperature range for liquid filling of hard gelatin capsules. The excipients, apart from Dynasan-114 and PEG 20,000, showed satisfactory capsule filling properties at 70°C using a semiautomatic filling machine. Dynasan-114 (viscosity = 0.012 Pass at 70°C) leaked from the seals between the hopper and pump of the filling machine, whereas PEG 20,000 (viscosity = 24 Pas at 70?C) showed bridging of the molten polymer between successive capsule bodies during the filling process. The effect of disperse phase (lactose) particle size and concentration, and continuous phase (PEG) molecular weight on the apparent viscosity and filling properties of the non-Newtonian dispersions were investigated at 70°C. Satisfactory filling of the dispersions was achieved at 70°C up to a limiting concentration of disperse phase which was dependent upon disperse phase particle size and continuous phase molecular weight, and corresponded to a pronounced increase in apparent viscosity of the dispersion.     

球磨法制备磁流变液过程中转速对其性能的影响

以羰基铁粉为分散相,以硅油为连续相,采用高速球磨分散的方法制备磁流变液,考察了磁流变液制备过程中转速对其粘度、沉降稳定性、流变性能的影响。研究发现,球磨机的转速对磁流变液的粘度和沉降稳定性影响很大。随着球磨机转速的不断提高,其粘度呈现出先减小后增大的趋势,当转速为300r/min时,所获的零场粘度最低。其沉降稳定性与粘度有很好的对应关系,即粘度大的沉降速率慢,粘度小的则沉降速率快,在转速为400r/min,所获得的沉降稳定性最好,同时获得的剪切应力也最高。因此,在磁流变液组成成分不变的情况下,制备磁流变液的过程中可以通过改变球磨机的转速来改变磁流变液的零场粘度、沉降稳定性和流变性能。     

Formation and stability studies of multiple (w/o/w) emulsions prepared with newly synthesized rosin-based polymeric surfactants

The multiple (water-in-oil-in-water, w/o/w) emulsions were prepared using newly synthesized rosin-based polymeric surfactants. The oil phase used was liquid paraffin. These emulsions were evaluated for stability by various methods: conductivity, viscosity, particle size, and visual inspection. The stability studies were carried out at 37°C and 4°C for 1 month. The multiple emulsion prepared with polymer 7 was found to be more stable compared to the emulsions prepared with polymer 2.