• Journal of the Society of Cosmetic Scientists of Korea
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• v.20 no.1
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• pp.52-63
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• 1994

It was investigated that the effects of surfactant to cosurfactant ratio on the stability and rheological properties of o/w microemulsion. The stability of microemulsion was good in the surfactant to cosurfactant ratio 20/40 - 30/30. In the point of rheological properties, a yield stress meande the inner structure formation was detected and the area of hysteresis loop was increased with increasing of surfactant content of the ratio. The microemulsion prepared by the Microfluidizer was characterized by rheopetic.

• Journal of the Korean Applied Science and Technology
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• v.17 no.3
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• pp.167-173
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• 2000

The process variables for the manufacture of translucent microemulsion prepared with 2-octyl dodecanol, 12-hydroxy stearic acid cholesteryl , POE(40)HCO and 1,3-butandiol were examined initially (primary emulsion) and following aging for three months. The techniques empolyed in this study were particle size, turbidity, interfacial tension and microfluidizer. Particle size analysis and turbidity measurement to evaluate the emulsion stability were used. It was concluded that the process of the emulsification was an important indicator of the stability of the translucent microemulsion. From the particle size and and turbidity measurement of translucent microemulsion, adding the surfactant to the oil phase before the emulsification was found to be the most important factor for the stability of emulsions. We found that interfacial tension of the adding the surfactant to the oil phase is lower than that of the adding the surfactant to aqueous phase. In spite of hydrophilic surfactant, adding the surfactant to aqueous phase produced inferior emulsion to that to oil phase.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.875-881
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• 1998

Microemulsion is prepared by the method of phase inversion emulsification with d-limonene that is environmental friendly substance and nontoxic to human body as dispersed phase. Emulsifier used for preparation of microemulsion is nonionic surfactants, polyoxyethylene nonylphenyl ether. Stability of prepared microemulsion was estimated by the various method of ξ-potential, hydrodynamic diameter and electric conductivity. When d-limonene is emulsified by NP series, microemulsion is most stable and narrowly distributed at HLB value of 12.3(either one emulsifier or mixed emulsifiers). Stability of microemulsion is increased as the amount of emulsifiers is increased at same HLB value of 12.3. In the case of using the same amount of emulsifiers, number of produced micelle are relatively large as hydrodynamic diameter is small. Therefore, the state of microemulsion is stable and the electric conductivity is increased. One can determine that higher electric conductivity value means that microemulsion has more micelles and is more stable.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.18 no.1
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• pp.132-149
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• 1992

This study relates to a microemulsion gel which is applied in various cosmetic preparations because of good appearance, superior stability and a thin, uniform, non-greasy fi Am on the skin. Main object of this study is to elucidate the influence of polyol(clarifying agent and/or coupling agent in microemulsion) on microemulsion and to establish the optimum conditions for microemulsion gel formation in the view of superior consistency, stability, clarity and pick-up from a container. The constituents of the system are composed of water, polar ester oi1, nonionic surfactant and polyol. Using the three-component phase diagram and the tetrahedral-phase diagram, we have investigated the changes of transparence regions, consistency and resonance effect by an impact in microemulsion gel varying in polyol ratio. The results of this study showed that the variation in the content of water and couple ins agent has major influence on the microemulsion gel and the optimum formation region of microemulsion gel is the widest when the ratio of glycerine(coupling agent) to water is 63-75% It is believed that optimum use of polyol seems to be helpful to obtain the microemulsion gel containing maximum amount of oil phase with minimum amount of surfactant which is recently one of the major problems of cosmetic chemists.

• Journal of the Korean Applied Science and Technology
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• v.19 no.3
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• pp.167-173
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• 2002

The isoflavone as a derivatives of flavone is colorless crystalline compounds. It acts on synthesis of fibronectine, collagen III, collagen I in human normal fibroblast by same biological activity to animal hormone. In this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using microemulsion containing isoflavone. The results of microemulsion stability test by centrifugation, storage in incubator and circulation chamber showed that separation of phase did not appear after 30 days. By the skin flexibility test, it has confirmed efficiency and effect as cosmetics materials. As the result, the microemulsion showed that skin flexibility factor improved up to 7.6%. We could confirm that O/W type microemulsion was stable system.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.495-505
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• 1995

The O/W microemulsion systems were made from 2 or 4% (w/w) oil (soybean oil, olive oil or isopropyl myristate) and 10, 15 or 20% (w/w) Brij 96. They were compared with micellar solution of equivalent surfactant concentration m therms of physicochemical properties, and the solubilization of sudan IV. They were characterized by dynamic light scattering, stability, surface tension, viscosity and rheogram. The mean diameters of O/W microemulsion systems were 10-15nm, and those of Brij 96 micellar solutions were 18-19 nm. Both of them were monodisperse systems. The O/W microemulsion systems showed Newtonian flow and their apparent viscosities were lower than those of micellar solutions. The surface tensions of O/W microemulsion systems were increased or decreased depending on the types of oil used, when compared with those of micellar solutions. The O/W microemulsion systems were very stable, and did not show any flocculation or aggregation. Their mean diameters were not changed after three months. But oxidation was observed in microemulsions without nitrogen gas at high temperature. There was a significant improvement in the sudan IV solubffimtion in micromulsion compared with that m the micellar solution containing equivalent concentration of surfactant. The size distribution and mean diameters of O/W micromulsions were not changed when sudan IV was solubilized.

• Journal of the Korean Applied Science and Technology
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• v.20 no.1
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• pp.44-50
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• 2003

We studied on the preparation and evaluation of O/W type microemulsion containing "wax, liquid paraffine and quaternary ammonium salt". And also it was obtained to stability of microemulsions by mono ethylene glycol(MEG) addition. The microemulsions were generally prepared at 96${\sim}$97$^{\circ}C$ by the phase inversion method. We used polyoxyethylene(20) sorbitan monooleate(POE(20)SMO) and distearyl dimethyl ammonium chloride(D.D.A.C.) as the emulsifiers at microemulsion preparation. From the results, we could get best condition for microemulsion preparation, in case of oil phase, montanic ester wax ; 1.1wt%, paraffine wax ; 1.1wt%, liquid paraffine ; 3.1wt%, propylene glycol ; 0.6wt% and ethylene glycol monobutyl ether ; 0.6wt%, when the ratio(wt%) of D.D.A.C. and POE(20)SMO were 2 : 3. And also we could obtained that the distributed particle size of the final microemulsions were about 8${\pm}$1.5nm and the mean particle size was 7${\pm}$0.5nm. We got following results from final microemulsions that the percent of transmittance; 96${\sim}$98% at 700nm. And the microemulsion blended with MEG of 5${\sim}$15wt% showed smaller particle size and more stable distribution than non-containing MEG.

• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.68-71
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• 1986

Oil in water microemulsion which has many pharmaceutical applications was prepared and evaluated. As oil sources and emulsifier, two grades of oil and egg phosphatide were used, respectively. Vacuum high shear mixing and high pressure homogenizing were performed and in the homogenizing step, effect of the number of passes in the homogenizer on the stability of microemulsion was studied, using Coulter counter, photographic microscope and pH-meter. From above results, it was concluded that the stability of microemulsion made of refined soy-bean oil was better than that of food grade soybean oil and by five passes in the homogenizer at 6,000 psi, we could make stable microemulsion with average particle diameter below $1\;{\mu}m$, with no particle above $5\;{\mu}m$ and no significant change during 6 weeks stored.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.1
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• pp.145-158
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• 1997

Lipid를 이용하여 보다 안정한 microemulsion을 제조함에 있어 Zeta potential을 이요하여 비교 분석 하여 보았다. 실험 시 Lipid Base와 Cetyl phosphate의 함량변화가 particle size와 zeta potential에 미치는 영향에 대하여 실험을 수행하였으며, zeta potetial의 시간 경과에 따른 경시변황 대하뎌도 조사하여 microemulsion의 적정조건을 찾을 수 있었다. microemulsion과 emulsion에 대하여 안전성을 비교 관찰 하였다.

• Korean Journal of Materials Research
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• v.34 no.7
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• pp.315-320
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• 2024

In order to maximize the function and increase the compatibility of silicone hydrogel lens, this study compared and analyzed the properties of Amino modified silicone oil using mini and microemulsion technique, respectively. Optical and physical properties were evaluated by spectral transmittance, refractive index, water content, oxygen transmittance and contact angle measurements to evaluate the performance of the manufactured hydrogel lens. The spectral transmittance results revealed the copolymerization method lens showed 31 % of the visible light area, which did not satisfy the basic optical properties. However, the lens using the mini and microemulsion materials showed more than 90 % of the visible light area, satisfying the optical characteristics. In addition, all physical properties were superior to a basic hydrogel lens. The mini and microemulsion techniques effectively improved the stability and function of the ophthalmic hydrogel lens and are considered a promising ways of manufacturing an ophthalmic hydrogel contact lens with increased compatibility and stability.