The characterization of the semi-solid W/O/W emulsions with low concentrations of the primary polymeric emulsifier

Semi-solid multiple W/O/W emulsions with low concentrations (0.8, 1.6 and 2.4% w/w) of lipophilic polymeric primary emulsifier PEG-30-dipolyhydroxystearate (PDHS) have been formulated. Both emulsions, primary and multiple, were prepared with high content of inner phase (Phi1 = Phi2 = 0.8). All the formulations differ only in the lipophilic emulsifier concentration. Evaluating several parameters such as macroscopic and microscopic aspect, droplet size, accelerated stability under centrifugation and flow and oscillatory rheological behaviour, assessed the multiple systems. It is possible to formulate the semi-solid W/O/W multiple emulsions with low concentrations of PDHS as the primary emulsifier. It appeared that the highest long-term stable multiple emulsion with the lowest droplet size, the highest apparent viscosity and highest elastic characteristic, was the sample with the highest concentration (2.4% w/w) of the primary emulsifier.     

各相体积比对W/O/W复合乳状液性质的影响

目的：研究用两步乳化法制备W／O／W型复合乳状液时，第一相体积比（内水相与油相的体积比）、第二相体积比（初乳与外水相的体积比）对W／O／W型复合乳状液性质的影响；方法：采用两步乳化法制备W／O／W型复合乳状液，固定制备工艺条件，改变第一相体积比和第二相体积比的数值制备初乳和复乳，用离心分层稳定性评价复乳的稳定性，初乳的离心稳定性、黏度和复乳的粒度分布被测定；结果：随着第一相体积分数增大，初乳黏度增大，初乳和复乳的离心稳定性都提高，但是内水相的体积分数达到65％时，初乳表现出凝胶的外观，所制备的复乳的稳定性反而降低，当内水相的体积分数增加到70％的时候，初乳转相形成O／W型乳状液，不能进一步制备复乳；随着第二相体积分数的增大，复乳黏度线性增大，复乳滴的体积平均粒径减小，复乳的离心稳定性提高。初乳中内水相与油相的适宜的体积比及复乳中初乳和外水相的适宜体积比皆为1：1左右。     

The effect of the type and the concentration of the lipophilic surfactant on the stability and release kinetics of the W/O/W multiple emulsions

Stable multiple emulsions that contain different lipophilic surfactants in the internal aqueous phase have been formulated. The multiple systems were assessed by evaluating several parameters such as macroscopic aspect, droplet size, percent release and accelerated stability under centrifugation or elevated temperature. The effect of polymeric and monomeric surfactants on the release mechanism and stability was examined. An excess of monomeric surfactant in the oil phase enhances the release rate and decreases stability. The release rate can be decreased by an increase of the lipophilic surfactant concentration. It appears that the more the oil globule swells, the less hydrosoluble drug is released. As a result a high swelling capacity is associated with better stability.     

O/W emulsion and W/O/W multiple emulsion: physical characterization and skin pharmacokinetic comparison in the delivery process of caffeine

The aim of this study was to compare the characteristics of an O/W emulsion and a W/O/W emulsion, formulated with similar ingredients. The physical properties of these two types of vehicles were characterized first. Using three types of in vitro models, human skin biopsies, nitrate acetate cellulose membranes and human reconstituted epidermis, the delivery potential of each vehicle for one hydrophilic drug, caffeine, was compared. The assessment of physical parameters, such as particle size, conductivity and rheological behavior enabled the nature of the test emulsions to be clearly identified. Clear differences were observed in the ability of each type of emulsion to deliver caffeine. Whatever the nature of the membrane used for the pharmacokinetic study, the absorption of caffeine was roughly two-fold lower (2.6 for human skin) when the W/O/W multiple emulsion was used as the vehicle. The concomitant determination of physical and kinetic properties of these two test emulsions allowed the W/O/W multiple emulsion and a simple O/W emulsion to be clearly differentiated.     

酪蛋白酸钠-明胶制备S/O/W乳状液的稳定性

碳酸钙是一种常用的强化钙,然而,其悬浮稳定性差,易产生沉淀,严重限制了碳酸钙在食品加工中的应用.以固/油/水(S/O/W)乳状液形式负载碳酸钙,构建具有特定结构分布的钙-脂质微球,有望改善其溶解性和稳定性.本文以食品级碳酸钙为S相,大豆油为O相,酪蛋白酸钠-明胶为W相,构建S/O/W钙-脂质微球,研究不同质量分数明胶和...     

紫苏球蛋白乳化性及其O/W乳液的稳定性研究

将紫苏籽粉碎过60目筛后采用石油醚脱脂得到紫苏籽脱脂粉,采用osborne法提取紫苏球蛋白,研究其乳化性质,并将其应用于水包油(oil in water,O/W)乳液,进一步研究紫苏球蛋白浓度对乳液稳定性影响.结果表明,紫苏脱脂粉中球蛋白含量较高,其溶解性、乳化活性和乳化稳定性在pH 2～9,呈现U型曲线;球蛋白质量浓...     

Double emulsion (W/O/W) gel stabilised by polyglycerol polyricinoleate and calcium caseinate as mangiferin carrier: insights on formulation and stability properties

Mangiferin (MGF) is a phenolic compound isolated from mango, but its poor solubility significantly limits its use. In this study, MGF was embedded into the inner aqueous phase of W₁/O/W₂ emulsions. Firstly, the dissolution method of MGF was determined. MGF remained stable in solution with pH 13 at 30 min, and its solubility reached 10 mg mL⁻¹. When the pH of MGF solutions was adjusted from pH 13 to pH 6, MGF did not immediately crystallise, providing sufficient time to construct the MGF-loaded W₁/O/W₂ emulsions. Subsequently, the MGF-loaded W₁/O/W₂ emulsions were constructed using polyglycerol polyricinoleate (PGPR) and calcium caseinate (CAS). The formation and stability of the W₁/O/W₂ emulsions were investigated. The MGF-loaded W₁/O/W₂ emulsions stabilised with 1% PGPR and 1% – 3% CAS exhibited a low viscosity, limited loading capacity, and poor stability. Conversely, the MGF-loaded W₁/O/W₂ emulsions stabilised by 3%PGPR–3%CAS exhibited optimal loading capacity (encapsulation efficiency = 95.31% and loading efficiency = 0.91%) and stability, which was attributed to the fact that high viscosity and gel state retarded the migration of inner aqueous phase. These results indicated that the W₁/O/W₂ emulsions stabilised by PGPR and CAS may be a potential alternative for encapsulating mangiferin.     

Formulation and characterisation of O/W emulsions stabilised with modified seaweed polysaccharides

In this study, seaweed polysaccharides (alginate and carrageenan) were modified with dodecenylsuccinic anhydride (DSA), and their stabilising properties in oil-in-water (O/W) emulsion system were evaluated. The physicochemical characteristics were determined by droplet size, interfacial tension and ζ-potential and structurally verified by Fourier transform infrared spectroscopy (FTIR). Both CRG-DSA and ALG-DSA applied in O/W emulsion system exhibited smaller droplet sizes over the increasing concentration and were more stable during storage than native ones. The ζ-potential of DSA-modified seaweed polysaccharides has more negative charge compared with their native forms, owing to the additional carboxyl groups from modification reaction. In addition, DSA-modified seaweed polysaccharides decreased the interfacial tension at soybean oil–water interface from 23.1 and 23.9 mN m⁻¹ to 14.2 and 13.6 mN m⁻¹, respectively. The successful modification reaction was confirmed by FTIR analysis. This study demonstrated that DSA-modified seaweed polysaccharides may serve as prospective emulsifiers in food, pharmaceutical and other industrial fields.     

酒精对酪蛋白酸钠溶液及O/W乳状液的影响

介绍了酒精对酪蛋白酸钠溶液及酪蛋白稳定的O/W乳状液性质的影响 .试验表明酒精在一定程度上可以降低酪蛋白酸钠的溶解度 .界面张力的测定则表明酒精的存在在很大程度上可以降低油—水界面和油—酪蛋白溶液界面的界面张力 .含酒精的乳状液体系的粘度会由于酒精的存在而提高 ,在酒精体积分数达 3 0 %时 ,乳状液体系的粘度会突然大幅度升高 .通过O/W乳状液的分层稳定性测定可发现 ,低浓度的酒精可以提高酪蛋白稳定的乳状液的分层稳定性 ,但酒精质体积分数超过 3 2 %时 ,乳状液的分层稳定性会受到破坏 .含酒精的O/W乳状液体系中油相含量的提高在一定范围内可以提高乳状液的稳定性 ,但高分散相浓度的含酒精的乳状液体系中由于连续相中酒精浓度的提高使乳状液体系稳定性下降 .     

亲脂性乳化剂的性质和用量对W/O/W型复合乳状液稳定性的影响

研究了亲脂性表面活性剂的性质和用量对W/O/W型复合乳状液稳定性的影响,采用两种类型的亲脂性表面活性剂：新型的聚合型高分子表面活性剂聚氧乙烯（30）二聚羟基硬脂酸脂（Arlacel P135）和传统的小分子表面活性剂Span80和Tween80的混合物（质量比9∶1,HLB=5.4）制备复乳。采用离心保留率、光学显微镜和黏度等方法评价初乳和复乳的稳定性。结果表明,与小分子表面活性剂Span80和Tween80的混合物相比,大分子聚合表面活性剂Arlacel P135可以显著地提高复合乳状液的稳定性,在优化的条件下复乳的稳定性可以达到2000r/min离心15min不分层。     

壳聚糖W/O型乳状液的超声辅助制备及其稳定性

以非牛顿假塑性大分子壳聚糖溶液为水相,棕榈油为油相,Span-80为乳化剂,采用单因素试验及响应面试验优化超声协助制备W/O型乳液工艺,并考察优化条件下制备的乳液稳定性.结果表明:内水相含量是影响乳液粒度大小的关键因素,且超声功率对乳液的粒度及其分布存在过处理现象.优化工艺为超声功率300 W、超声时间15 min、内...     

超声处理大豆分离蛋白与壳聚糖复合物对O/W型乳液稳定性的影响

为探究超声处理大豆分离蛋白-壳聚糖（soybean protein isolate-chitosan,SPI-CS）复合物对形成O/W型乳 液性质的影响,主要研究了复合物表面疏水性、乳化活性、乳化稳定性与油-水界面张力、乳液粒径、乳液稳定性 之间的关系。结果表明：未经超声处理的SPI-CS复合物表面疏水性、乳化活性、乳化稳定性和界面吸附性较低,形 成的O/W型乳液粒径相对较大,约100 μm,乳液Zeta电位较低,乳滴有发生聚集的倾向。乳液贮存7 d后乳层析指数 最高。经超声处理后SPI-CS复合物形成的乳状液性质发生明显变化,随着超声功率的增加,形成的O/W型乳液的稳 定性有所增加：超声功率为400 W时SPI-CS复合物形成的乳液最为稳定,乳层析指数最低;当超声功率超过400 W 时,乳液的光学显微镜观察显示其粒径有所增大,同时乳液的Zeta电位、乳化活性和乳化稳定性明显下降,界面张 力降低缓慢。超声处理暴露了蛋白质分子的内部结构,使部分结构展开、柔性增加,促进了其与壳聚糖之间的静电 相互作用,说明超声处理的大豆分离蛋白与壳聚糖形成的复合物影响了O/W型乳液的稳定性及相关性质。     

一种水包油包胶型乳液的制备及其在乳化肠中的应用

以结冷胶和无水氯化钙为内水相凝固剂,酪蛋白酸钠为外水相乳化剂,制备一种水包油包胶（S/O/W）型 乳液。以多重乳液粒径和分布为指标,研究酪蛋白酸钠添加量对S/O/W型多重乳液加工适应性的影响。结果表明： 正交试验得到S/O型单重乳液最佳制备条件为：内水相中结冷胶添加量0.2%、无水氯化钙添加量0.5%;内水相乳化 剂聚甘油蓖麻醇酯添加量2.5%;油相为精炼猪油,油水体积比3∶2;剪切速率17 500 r/min,剪切时间1.5 min。将制 得的S/O型单重乳液与不同添加量酪蛋白酸钠混合制得S/O/W型多重乳液。当酪蛋白酸钠添加量0.1%时,S/O/W型 多重乳液粒径符合加工要求,且贮藏、热处理、剪切稳定性较好。以多重乳液替代猪脂肪制备的低脂乳化肠与高脂 （精炼猪油含量20%）乳化肠外观不存在明显差异;微观结构观察结果表明,多重乳液在乳化肠中包裹良好、分布 均匀。     

Formation of oil‐in‐water (O/W) pickering emulsions via complexation between β‐cyclodextrin and selected organic solvents

Cyclodextrins (CDs) are cyclic oligosaccharides derived from the enzymatic degradation of starch. Emulsifying functionality of β‐cyclodextrin (β‐CD) upon its complexation with selected solvents (octanol, decane, and toluene) was studied. In several tests, the three‐phase systems containing the emulsion fraction in the middle position were obtained. The examination of variations in the phase behavior of the test systems showed that the decane/β‐CD/water system had the highest emulsion phase volume when β‐CD at concentration of 10% w/v was used. A reduction in interfacial tension (IFT) of the oil–water interface in each test system was observed with the following order: toluene, decane, and octanol. The precipitated fraction obtained upon centrifugation of the emulsion phase, was structurally characterized as the inclusion complex (IC) formed between β‐CD and each of the three test solvents. The wettability of the IC particles was determined through contact angle measurement and formation of the oil‐in‐water (O/W) Pickering emulsions was confirmed (θ_ow<90°). With use of size distribution data, the ICs particles as the microparticles (1–10 µm) were found to be the main species involved in the formation and stabilization of the emulsions.