• Journal of Life Science
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• v.20 no.11
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• pp.1611-1616
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• 2010

The purpose of this research was to determine the effect of surfactant micelles on lipid oxidation in W/O/W multiple emulsions. The content of ferric irons and hydroperoxide in the continuous phase in W/O/W multiple emulsions was measured as a function of Brij micelle. The concentration of ferric iron and hydroperoxide in the continuous phase increased with increased storage time (1~6 days). Lipid oxidation rates, as determined by the formation of lipid hydroperoxides, TBARs and headspace hexanal, in the W/O/W multiple emulsions containing ferric iron decreased when 3% surfactant micelles were exceeded. These results indicate that excess surfactant micelles could alter the physical location and prooxidant activity of iron in W/O/W multiple emulsions.

• Membrane Journal
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• v.27 no.6
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• pp.511-518
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• 2017

The membrane emulsification (ME) is a technology for producing emulsions with narrow size distribution by using the well-defined porous membranes such as the SPG membrane. In this study, the preparation of polycaprolactone (PCL) microcapsules by using the multiple emulsions obtained from membrane emulsification method is studied. After the making of $W_1/O$ single emulsions by sonication method, then $W_1/O/W_2$ multiple emulsions are formed by premix-ME method. The PCL microcapsules impregnated with BSA model drug are prepared by solvent evaporating from $W_1/O/W_2$ multiple emulsions. The effects of various parameters such as the ratio of disperse/continuous phase (D/C ratio), the concentration of PCL, emulsifier and model drug and the transmembrane pressure on the size and distribution of PCL microcapsules are investigated. The uniform PCL microcapsules with about $5{\sim}6{\mu}m$ of mean size and 26% of BSA loading are obtained by the premix membrane emulsification.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.733-737
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• 2012

This study reports the microfluidic preparation of monodisperse multiple emulsions using hydrodynamic control. To generate multiple emulsions, we fabricate a microfluidic capillary device based on co-flowing stream without any surface modification of microchannels. Based on the system, we can successfully generate multiple emulsions (W/O/W) using water containing 0.5 wt% Tween 20, n-hexadecane with 5 wt% Span 80, and 10 wt% poly (vinyl alcohol) (PVA) aqueous solution, respectively. Furthermore, we control the number of inner droplets by modulation of flow rate of inner fluid at fixed flow rate of middle and outer fluid. The multiple emulsions having precisely controlled inner droplets' size and number can be applicable for multiple chemical reactions as an isolated microreactor.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.237-246
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• 2014

Multiple emulsions, called multiphase emulsions, include water-in-oil-in-water (W/O/W) type and oil-in-water-in-oil (O/W/O) type emulsions. In cosmetic industry, they are used to stabilize active ingredients but the applicability of the multiple emulsions is limited because of low stability and difficulty of manufacturing. In this study, we investigated a two-step emulsification process for a W/O/W type emulsion. We also investigated the change of stability using different emulsifiers and oil polarity. The results suggested that polyglyceryl-10 stearate, as a main emulsifier, played an important role in the stability and the formation of the multiple emulsions.

• KSBB Journal
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• v.27 no.4
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• pp.207-214
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• 2012

Emulsions are mixture of immiscible liquids in which one is dispersed in all over the other. They have been applied to many applications including cosmetics, foods, drug delivery system (DDS), fine chemicals, and chemical separations. Especially, emulsion technology is one of the most useful technique to formulate cosmetics such as eye cream, foundation, and foam cleansing. In general, the emulsions can be generated by mechanical agitation of two immiscible fluids. However, the emulsions obtained by conventional method have limited in stability, monodispersity, and complicate process. We describe here preparation techniques of representative cosmetic emulsions such as liposome, liquid crystal emulsion, nanoemulsion, multiple emulsion, and pickering emulsion. Furthermore, various factors which can control the physical properties of each cosmetic emulsions are briefly discussed.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.715-721
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• 1997

W/O/W multiple emulsions were prepared comprising $MgSO_4$ in the inner aqueous phase as a model drug. The stability and drug release behavior of the multiple emulsions were studied using optical microscopy, viscometry and conductometry. Glucose was introduced in the outer aqueous phase to reduce the osmotic pressure gradient across the oil layer arising from the localization of drug molecules in the inner water phase. It was found that the presence of glucose was effective in stabilization of the multiple emulsions and in control of the release rate of drug more evidently when oil phase was partially hydrophilized with cetostearyl alcohol. This may be attributed to the fact that the migration of water accompanying the hydrophilic surfactant to the inner water phase was limited under a reduced osmotic pressure gradient and thereby slow down the destabilization of the oil/inner water interface.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.47-50
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• 2004

Since emulsion liquid membrane (ELM) was found by Li in the late 1960s$^{[1]}$ , a great amount of work has been conducted on the research and application of ELM$^{[2-8]}$ . Generally, during a process of ELM separation, three types of emulsions will be shown in turn. They are primary emulsion, multiple emulsion, namely ELM, and recovered emulsion respectively. Those three types of emulsions inevitably share some common properties, and at the same time, because those three types of emulsions emerge in different stages of ELM separation, some differences will be observed.(omitted)

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.560-567
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• 1997

A new approach to obtain stable $W_1/O/W_2$ multiple emulsions has been studied ; The basis of the interfacial interaction between a PCL-PEO-PCL triblock copolymer and a lipophilic emulsifier in the dispersed oil phase was examined. $W_1/O/W_2$ multiple emulsions were prepared by the two-step method. Arlacel P-l35 was used as a liphophilic emulsifier and Synperonic PE/F 127 as a hydrophilic one. Eutanol-G was used as an oil phase. NaCl was encapsulated within the multiple emulsion droplets as the internal marker and its release rate studies were carried out. The suability of the multiple emulsions have been assessed by measuring Separation Ratios(%) and microscopic observations. The release of NaCl was significantly reduced in $W_1/O/W_2$ multiple emulsions containing PCL-PEO-PCL triblock copolymer(2k-4k-2k or 6k-4k-6k) in the oil phase. It may be concluded that the copolymer and the emulsifier form effective interfacial complex to enhance stability and to control the release rate. The effective diffusion coefficients of the NaCl were estimated as $2.64{\times}10^{-15}s$and $3.23{\times}10^{-16}gcm^2/s$ for the $W_1/O/W_2$ multiple emulsion containing 1.2 wt % of PCL-PEO-PCL triblock copolymers with compositions of 2k-4k-2k and 6k-4k-2k, respectively. The rate of release decreased with the increase of the initial concentration of NaCl. The results were examined in view of Higuchi mechanism. A kinetic model which is similar to the model for release of dispersed drugs from a polymeric matrix was found to be suitable for the release of NaCl from $W_1/O/W_2$ multiple emulsions.

• Polymer(Korea)
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• v.36 no.2
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• pp.177-181
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• 2012

This study presents the preparation of double emulsions in a poly(dimethylsiloxane) (PDMS)-based microfluidic device. To improve the wettability of hydrophilic continuous phase onto a hydrophobic PDMS microchannel, the surface was modified with 3-(trimethoxysilyl) propyl methacrylate (TPM) and then sequentially reacted with acrylic acid monomer solution, which produced selective covalent bonding between acrylic acids and methacrylate groups. For the proof of selective surface modification, tolonium chloride solution was used to identify the modified region and we confirmed that the approach was successfully performed. When water containing 0.5% w/w sodium dodecyl sulfate and 1% w/w Span80 with hexadecane were loaded into the selectively modified microfluidic channels, we can produce stable double emulsion. Based on the spreading coefficients, we predict the morphology of double emulsions. Our proposed method efficiently produces monodisperse double emulsions having 48.5 ${\mu}m$(CV:1.6%) core and 65.1 ${\mu}m$ (CV:1.6%) shell. Furthermore, the multiple emulsions having different numbers of core were easily prepared by simple control of flow rates.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.759-760
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• 2000

5-fluorouracil loaded chitosan-cellulose microspheres was prepared by W/O/W multiple emulsions solvent evaporation technique which is appropriate to oral drug delivery. The influences of process parameters on the physical characteristics of microspheres and on in vitro drug release were investigated.