• Journal of Pharmaceutical Investigation
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• v.34 no.5
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• pp.369-377
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• 2004

The objective of this study was to investigate the patterns of protein leaching to an external phase during an ethyl acetate-based, double emulsion microencapsulation process. An aqueous protein solution (lactoglobulin, lysozyme, or ribonuclease; $W_1$) was emulsified in ethyl acetate containing poly-d,l-lactide-co-glycolide 75:25. The $W_1/O$ emulsion was transferred to a 0.5% polyvinyl alcohol solution saturated with ethyl acetate $(W_2)$. After the double emulsion was stirred for 5, 15, 30, or 45 min, additional 0.5% polyvinyl alcohol $(W_3)$ was quickly added into the emulsion. This so-called quenching step helped convert emulsion microdroplets into microspheres. After 2-hr stirring, microspheres were collected and dried. The degree of protein leaching to $W_2$ and/or $W_3$ phase was monitored during the microencapsulation process. In a separate, comparative experiment, the profile of protein leaching to an external phase was investigated during the conventional methylene chloride-based microencapsulation process. When ethyl acetate was used as a dispersed solvent, proteins continued diffusing to the $W_2$ phase, as stirring went on. Therefore, the timing of ethyl acetate quenching played an important role in determining the degree of protein microencapsulation efficiency. For example, when quenching was peformed after 5-min stirring of the primary $W_1/O$ emulsion, the encapsulation efficiencies of lactoglobulin and ribonuclease were $55.1{\pm}4.2\;and\;45.3{\pm}7.6%$, respectively. In contrast, when quenching was carried out in 45 min, their respective encapsulation efficiencies were $39.6{\pm}3.2\;and\;29.9{\pm}11.2%$. By sharp contrast, different results were attained with the methylene-chloride based process: up to 2 hr-stirring of the primary and double emulsions, less than 5% of a protein appeared in $W_2$. Afterwards, it started to partition from $W_1\;to\;W_2/W_3$, and such a tendency was affected by the amount of PLGA75:25 used to make microspheres. Different solvent properties (e.g., water miscibility) and their effect on microsphere hardening were to be held answerable for such marked differences observed with the two microencapsulation processes.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.344-352
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• 1993

The purpose of this study is to investigate the possibility of the non-destructive quality evaluation for food by the acoustic non-linear parameter B/A which is a measure of the non-linearity of the state equation of the medium in terms of pressure and density. The B/A of water, corn oil O/W(oil in water) emulsion and milk were measured by using a sound velocity measuring system. The B/A value of water was measured for ascertaining reliability of our experimental system. Corn oil W/W emulsion was prepared as a model of milk . It was proved that the B/A value of O/W emulsion was related to the oil concentration by a law of mixture. We applied this result to milk and obtained satisfactory results for predicting the milk fat concentration.

• Clean Technology
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• v.14 no.4
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• pp.256-264
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• 2008

In this study, using PBAST (poly(butylene adipate-co-succinate-co-terephthalate)) which was eco-friendly biodegradable aliphatic polyester, PBAST/PVA (poly(vinyl alcohol)) double-layered hollow microspheres were prepared with the water/oil/water multiple emulsion ($W_1/O/W_2$) method. The double-layered hollow microspheres were manufactured with the yield of 30.92% when the concentration of polymer PBAST in organic phase was 5 wt%, the concentration of PVA in inner aqueous phase was 5 wt%, the volume ratio of $W_1/O$ emulsion to outer aqueous phase was 1:4.5, and when co-surfactants that had large gap in HLB (hydrophile-lipophile balance) value were used. The bulk density of prepared hollow microsphere was 0.180 g/ml and particle size was $1.5{\sim}3\;{\mu}m$.

• Membrane and Water Treatment
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• v.13 no.4
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• pp.201-208
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• 2022

Emulsion Liquid Membrane (ELM) is a prominent technique for the separation of heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of the components (Surfactant and Carrier) of ELM is a very significant step for its preparation. In the ELM technique, the primary water- in-oil (W/O) emulsion is emulsified in water to produce water-in-oil-in-water (W/O/W) emulsion. The water in oil emulsion was prepared by mixing the membrane phase and internal phase. To prepare the membrane phase, the extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2- ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II). Emulsion Liquid Membrane (ELM) is a well-known technique for separating heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of ELM components (Surfactant and Carrier) is a very significant step in its preparation. In the ELM technique, the primary water-in-oil (W/O) emulsion is emulsified to produce water-in-oil-in-water (W/O/W) emulsion. The water in the oil emulsion was prepared by mixing the membrane and internal phases. The extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2-ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II).

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.767-772
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• 2006

In this study, we sought to produce a double layer microcapsule containing Lactobacillus sp. as the core material. The conditions for this microencapsulation process were optimized for the formation of a microcapsule with high storage stability. The effects of the ratio of[core material] to [wall material], the type and concentration of emulsifier used, the stirring rate(dispersibility) and the temperature of the dispersion fluid on the microencapsulation yield were studied. The optimal concentration and type of emulsifier required in order to allow for the stable formation of a W/O type emulsion (a primary process in double layer microencapsulation) were 1.00% (w/w) and polyglycerol polyricinileate (PGPR, HLB 0.6). However, the optimal concentration and type of emulsifier required to construct a W/O/W type emulsion (a secondary process in double layer microencapsulation), were 0.65% (w/w) and polyoxyethylene sorbitan monolaurate (PSML, HLB 16.7). Finally, we obtained a maximum yield of microencapsulation with a dispersion fluid stirring rate of 270rpm and a dispersion fluid temperature of 10$^{\circ}C$ after spraying a W/O/W type emulsion into the dispersion fluid.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.469-479
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• 2015

This study is related to the developing method of a transparent sunscreen cosmetic which has waterproofing property and no white turbidity when applied to skin. The transparent sunscreen is prepared by exploiting refractive index difference between oil-phase and water-phase of water-in-oil(W/O) emulsion. The sunscreen according to this study is prepared as a W/O type emulsion so that it is water-stable and water resistance. Also, the stability of W/O type emulsion is developed by adjusting the content of oil phase part and water phase part. As a result of this studying, the transparent W/O emulsion is prepared by adjusting the refractive index of oil-phase and water-phase within 0.004 and it is found that the stability of the transparent sunscreen is increasing when the water phase part is over 75% (w/w) of the W/O emulsion. Through clinical test of transparent sunscreen, the value of sun protection Factor(SPF) and Protection Factor of UVA(PFA) were determined. SPF and PFA values of transparent sunscreen were indicated $30.99{\pm}1.65$ and $3.01{\pm}0.30$.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.999-1005
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• 2007

An oil-in-water (O/W) emulsion [20 wt% com oil, 0.5-6.0 wt% fish gelatin (FG), pH 3.0] was produced by high pressure homogenization, and the influence of pH, protein concentration, and homogenization condition on the formation of FG-stabilized emulsions was assessed by measuring particle size distribution, electrical charge, creaming stability, microstructure, and free FG concentration in the emulsions. Optical microscopy indicated that there were some large droplets ($d>10\;{\mu}m$) in all FG-emulsions, nevertheless, the amount of large droplets tended to decrease with increasing FG concentration. More than 90% of FG was present free in the continuous phase of the emulsions. To facilitate droplet disruption and prevent droplet coalescence within the homogenizer, homogenization time was adjusted in O/W emulsions stabilized by 2.0 or 4.0 wt% FG. However, the increase in the number of pass rather promoted droplet coalescence. This study has shown that the FG may have some limited use as a protein emulsifier in O/W emulsions.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.694-701
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• 2015

In order to get stabilized pure retinol in skin care cosmetics, developing the three layered matrix bead capsules were studied. This study relates to make a cosmetic composition using the three layered matrix capsule that could increase the stability of the active ingredient. A primary encapsulation, vitamin A (pure retinol) of active ingredient was perfectly capsulated into water-in-oil (Water-in-Oil: W/O) emulsion vesicle using PEG-10 dimethicone copolyol emulsifier. A secondary encapsulation of multiple emulsion of the water-in-oil-in-water (W/O/W) emulsion blending W/O emulsion using sucrose distearate of surfactant was developed using homogenizing emulsifying system. Pure retinol of active ingredient was stably capsulized to inside the W/O/W-multiple emulsion in order to load the triple matrix capsulation. By coating it with a polymer matrix base, encapsulated in the triple layered type, which were developed bead encapsulation of 2~10mm uniformly size. To show beautifully appearance capsulated bead type, these finish particles in this triple matrix layer were developed as a gold, green, dark brown, silver and blue color were encapsulated in the bead types. Structural particle certification of triple matrix layer was observed through SEM analysis. Stability of pure retinol was remained stable more than 99.7% for 30 days at $42^{\circ}C$ incubating conditions compared with non-capsule. This technology was applied in different formulations such as various sizes and colors that by applying the skin care cosmetics. In the future, this technology to encapsulate an unstable active ingredient, we expect to be expanded this application in the food and drug as a time delivery system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.38-44
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• 1998

The skin permeation and the skin primary irritation of two UV filters from caprylic capryl triglyceride (oil), oil in water (O/W) and water in oil (W/O) emulsions, were evaluated. We selected octyl moth-oxycinnamate (OMC) broadly used in cosmetics and polymeric sunscreen agent (PSA, average MW: 2,000) synthesized by the coupling reaction of 2-ethylhexyl 4-hydroxycinnamate with poly vinylbenzyl chloride, as model UV filters. For in vitro skin permeation experiments, Franz diffusion cells (effective diffusion area:1.766cm) and the excised skin of female hairless mouse aged 8 weeks were used. Oil or emulsion containing UV filters was applied in the donor compartment. The skin primary irritation was evaluated with fe-male guinea pigs (8-10 weeks,350-400 g). In oil and emulsions, the skin permeability and the skin primary irritation of PSA were lower than those of OMC. The skin permeability of UV filters was lower when they were in oil-in-water emulsion (OIW) than water-in-oil emulsion (W/O). We suggest that O/W system would be more useful when compared with W/O system, and PSA could be a good candidate for a future sunscreen agent for reducing the skin irritation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.2
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• pp.103-110
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• 2009

The objective of this study is to analyze the influences of fatty alcohols and fatty acids on rheological properties of oil in water (O/W) emulsions using viscosity and rheograms. As the chain length of fatty alcohols and fatty acids lengthened, the viscosity of emulsions was increased. The influence of fatty alcohols on viscosity enhancement was stronger than that of fatty acids. Both stearyl alcohol and cetearyl alcohol, which have carbon chain length similar to lipophilic portion of surfactant used in emulsion preparation, had showed the best increase in viscosity of O/W emulsions. O/W emulsions prepared with fatty alcohols and fatty acids were pseudo-plastic fluid and they showed shear thinning behaviour like as the common cosmetic emulsions. O/W emulsions prepared with cetyl alcohol, cetearyl alcohol and stearyl alcohol were thixotropic fluids and thixotropy increased with an increase in the concentration of fatty alcohols and fatty acids. Also O/W emulsions prepared with fatty alcohols were more thixotropic than those prepared with fatty acids. For the sake of viscosity increase related to O/W emulsions stability and spreadability enhancement related to payoff, it is thought that fatty alcohols are more useful than fatty acids in the O/W emulsions as the emulsion stabilizer.