• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.121-127
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• 2003

The objective of this study was to solidify the simvastatin self-microemulsifying drug delivery system (SMEDDS) and to improve the encapsulation efficiency of solidified alginate beads using sodium alginate. Typical simvastatin SMEDDS was composed of various oils, surfactants and cosurfactants. Also solidified-alginate beads was prepared by crosslinking liquid emulsion mixtures containing sodium alginate and other excipients (cetylpyridinum chloride (CP-Cl), hydroxypropyl methylcellulose, starch and so on). in $CaCl_2$ solution, it has been investigated that the drug release pattern and encapsulation efficiency were varied with the ratio of cationic lipid (CP-Cl). Solidified sodium alginate beads containing simvastatin SMEDDS were redispersed into media without re-aggregation. Oil droplet size of redispersed solidified-beads in media produced smaller than the initial size. The density of beads and drug loading amount were increased with increasing cationic lipid content. These systems have advantages of storage stability and predictability of drug release rate.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.103-108
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• 1998

A hydrophobic substrate triolein was hydrolyzed by lipase in a mono-phase reaction system containing cyclodextrin(CD) as emulsifier. The triolein was transformation to an emulsion-like state in the CD containing reaction system in contrast to the oil-droplet like state without CD due to the formation of an inclusion complex between the lipids and CDs. The hydyrolysis reaction increased substantially in the CD containing reaction system, and the optimum reaction conditions including the amount of lipase, ${\beta}$-CD concentration, and mixing ratio of triolein and ${\beta}$-CD, were determined. The performance of the enzyme reaction in a mono-phase reaction system was compared with that of a two-phase reaction system which used water immiscible hexane as the organic solvent. The role of a CD in the mono-phase reaction system was elucidated by comparing the degree of the inclusion complex formation with triolein and oleic acid, Km and Vmax values, and product inhibition by oleic aicd in aqueous and CD containing reaction systems. The resulting enhanced reaction seems to be caused by two phenomena; the increased accessibility of lipase to triolein and reduced product inhibition by oleic acid through the formation of an inclusion complex.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.596-610
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• 2021

For application in adsorption process, we synthesized silica nanospheres by Stober method, and silica particles with wrinkled surface as well as macroporous silica particles were also fabricated by utilizing emulsion droplet as micro-reactors, followed by modification of the particle surface using suitable coupling agents containing amine groups. These particles exhibited improved adsorption capacity for heavy metal ions and anionic dyes, which were difficult to be removed by conventional silica particles without surface modification. Anionic dye, methyl orange could be removed almost completely by adsorption using porous silica particles modified using APTES. The adsorption efficiency of heavy metal like copper ions was close to 100%, when porous silica was used as adsorbent particles modified with AAPTS.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.3
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• pp.237-243
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• 2015

In this study, the effects of the mixing ratio of emulsified fuel on the droplet evaporation and spray behavior characteristics were analyzed. A surfactant comprising span 80 and tween 80 mixed at a 9:1 ratio was used for the emulsified fuel. The fuel and surfactant were mixed at a ratio of 3:1 for the emulsified fuel. In addition, considering the mixing ratio of the surfactant, the mixing ratio of $H_2O_2$ in the emulsified fuel was set as EF (emulsified fuel)0, EF2, EF12, EF22, EF32, and EF42. To observe the evaporation characteristics, droplets of the emulsified fuel were dropped on a heating plate and observed using scattered light and a Schlieren system. In addition, to analyze the effect of the $H_2O_2$ mixing ratio, the behavior characteristics of the evaporative free spray were investigated in the mixing ratio range of EF0 to EF22 using a constant volume chamber with heaters. Consequentially, it was found that in the case of EF22, the free spray development of the emulsified fuel was faster than that of EF0 (diesel only) because of the promotion of the evaporation due to the phase change in the peroxide contained in the emulsion fuel.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.217-223
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• 2015

We investigated the emulsifying properties of barley octenyl succinic anhydride (OSA)-${\beta}$-glucan, such as changes in the fat globule size and zeta-potential as influenced by pH or the addition of NaCl. Additional experiments to fabricate a suitable co-surfactant system were also performed. We found that the fat globule size in OSA-${\beta}$-glucan emulsions increased upon lowering the pH (i.e., under acidic conditions) or increasing the NaCl concentration. These results were confirmed through microscopic observation. Co-surfactant hydrophilic Tween 20 was found to be suitable for the OSA-${\beta}$-glucan emulsion, which facilitated the formation of smaller fat globules and enhanced the creaming stability when it was added in >0.2 wt% concentration. From the results of the surface load of OSA-${\beta}$-glucan in emulsions, Tween 20 addition enhanced the stability probably by the co-adsorption of the two surfactants at the droplet surface.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.365-374
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• 2021

In this study, the effect of enzyme-modified starch used in the preparation of filled hydrogel powder loaded with curcumin (FHP) on redispersibility, thermal and UV stability, and curcumin retention during in vitro digestion was investigated. FHP maintained stability without layer separation when redispersed and showed more stability against UVB than the emulsion powder (EMP). There was no significant difference in the chemical stability of curcumin between rice starch-based filled hydrogel powder (RS-FHP) and enzyme-modified starch-based filled hydrogel powder (GS-FHP). However, the gel matrix of GS-FHP maintained greater stability of lipid droplets in the stomach compared to RS-FHP, thereby improving the retention rate of curcumin after in vitro digestion. GS-FHP could be used as a novel material for developing premixes that require stable formulation and maintenance of functional substances, as it can increase the dispersion stability and retention rate of functional substances after digestion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.231-236
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• 2021

The Aphid, Myzus persicae, and the bean bug, Riptortus clavatus, are major insects in crops. This study examined the insecticide susceptibility and phytotoxicity of insecticides dispersed using an Unmanned Aerial Vehicle (UAV, multi-copter) against the insects. Sulfoxaflor suspension concentrate (SC, 16X) on potato fields and etofenprox, methoxyfenzide suspo-emulsion(SE, 8X) on soybean fields were dispersed after deploying water-sensitive paper within the field to measure the distribution pattern and coverage index of the falling insecticide. Both insecticides showed a controlled mortality of 76.4% against aphids and 97.5% and 94.4% against the 2nd nymphal, and 5th nymphal stage of the bugs, respectively. The droplet distribution was less than 0.5mm, and coverage analysis revealed an inside and outside coverage of 3.1 and 1.6, respectively. The surrounding area was affected by insecticide spraying using a multi-copter. This study is expected to help expand UAV control and use it safely in the future.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.484-495
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• 2020

This study is a mixed surfactant (MimicLipid-MSM1000) that forms the same structure as that of the stratum corneum, sucrose distearate, polyglyceryl-2 dioleate, fermented squalane, ergosterol, 10-hydroxystearic acid, mixture consisting of was synthesized. When using 2~5 wt% of this mixed surfactant, it was possible to make an artificial skin mimetic that forms a multi-layer lamellar structure of 5~30 layers. An emulsion was prepared using this mixed surfactant, and a multi-layered lamellar phase was formed and analyzed mechanically. The appearance of this surfactant was a light brown hard wax, the hydrophilic lipophilic balance (HLB) was 12.53, the critical parameter value was 0.987, and the acid value was 0.13. Stability according to pH change was also stable in acidic (3.8), neutral (7.2) and alkaline (10.8). The particle size of the liquid crystal was found to be the most stable maltese cross lamellar crystalline droplet at 5~25mm. The size of the emulsified particles according to the change in the speed of the homo agitator is 2500 rpm (17.9mm±2.6mm), 3500rpm (12.5mm±2.1mm), 4500rpm (6.2mm±1.8mm) particles were formed. Liquid crystal forming particles were observed through a polarization microscope, and the formation structure of the liquid crystal was precisely analyzed with a scanning electron microscope (cryo-SEM). As an application field, it is expected that it will be widely applicable to the development of various prescriptions, such as various skin care cosmetics, makeup care cosmetics, and scalp protection cosmetics, by using a skin-mimicking surfactant.