• Journal of Pharmaceutical Investigation
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• v.28 no.3
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• pp.141-149
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• 1998

In order to reduce systemic side effects following administration, flurbiprofen was formulated as O/W microemulsion consisting of the surfactant, oil phase and aqueous phase. Particle size distribution, apparent viscosity, solubility and skin permeation of flurbiprofen in various vehicles and microemulsion were evaluated. The domain of O/W microemulsion s phase diagram had difference between oil types and the area of O/W microemulsion was wide distributed by adding to PG and cosurfactant than that of water alone. As increasing 10, 15 and 20% of Brij 97 content and 1, 2.5, 5% of oil content, the solubility of flurbiprofen in O/W microemulsions and various vehicles was $400{\sim}1,000$ and $10{\sim}500$ times higher than that of control. Also, apparent viscosity of soybean oil microemulsions was higher than that of IPM microemulsions and that of vehicle were increased as increasing vehicle content. Since skin permeation of flurbiprofen decreased as increasing viscosity, in each vehicle, it was not affected 2% ${\beta}-CD$ and decreased as increasing PG content and to 2, 5 and 10% of $HP-{\beta}-CD$. In O/W microemulsion, 5% soybean oil. 20% Brij 97 and 75% water(A-1) with high viscosity showed low skin penetration.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.392-404
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• 2003

A new technology to achieve o/w microemulsions allows the formulation of transparent products with low surfactant content. The PIT Nanotechnology approach gives cosmetic/pharmaceutical o/w microemulsions in one step with a broad variety of surfactants, cosurfactants and oil phases.

• Journal of the Korean Applied Science and Technology
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• v.19 no.1
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• pp.56-62
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• 2002

Microemulsion is stable to aggregation, sedimentation, fusion and has $3nm{\sim}200nm$ of particle size which is transparent and semitransparent. The isoflavone as a derivatives of Flavone is colorless crystalline compounds. It has similar basic structure to steroid materials which is hormone that acts to skin physiological phenomenon. On this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using O/W type microemulsion containing isoflavone. We manufactured O/W microemulsions by phase inversion emulsification method. It's was found that POE(20) monostearate with HLB value 14 caused microemulsion to be formed, which had $4nm{\sim}18nm$ of average diameter and $3nm{\sim}33nm$ of particle size distribution. Apparent viscosities of the microemulsions have increased in proportion to add surfactant dose.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1598-1609
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• 2013

Organochlorine pesticide residues continue to remain as a major environmental threat worldwide. Lindane is an organochlorine pesticide widely used as an acaricide in medicine and agriculture. In the present study, a new lindane-degrading yeast strain, Pseudozyma VITJzN01, was identified as a copious producer of glycolipid biosurfactant. The glycolipid structure and type were elucidated by FTIR, NMR spectroscopy, and GC-MS analysis. The surface activity and stability of the glycolipid was analyzed. The glycolipids, characterized as mannosylerythritol lipids (MELs), exhibited excellent surface active properties and the surface tension of water was reduced to 29 mN/m. The glycolipid was stable over a wide range of pH, temperature, and salinity, showing a very low CMC of 25 mg/l. Bio-microemulsion of olive oil-in-water (O/W) was prepared using the purified biosurfactant without addition of any synthetic cosurfactants, for lindane solubilization and enhanced degradation assay in liquid and soil slurry. The O/W bio-microemulsions enhanced the solubility of lindane up to 40-folds. Degradation of lindane (700 mg/l) by VITJzN01 in liquid medium amended with bio-microemulsions was found to be enhanced by 36% in 2 days, compared with degradation in 12 days in the absence of bio-microemulsions. Lindane-spiked soil slurry incubated with bio-microemulsions also showed 20-40% enhanced degradation compared with the treatment with glycolipids or yeast alone. This is the first report on lindane degradation by Pseudozyma sp., and application of bio-microemulsions for enhanced lindane degradation. MEL-stabilized bio-microemulsions can serve as a potential tool for enhanced remediation of diverse lindane-contaminated environments.

• Journal of Pharmaceutical Investigation
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• v.39 no.6
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• pp.417-422
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• 2009

Budesonide belongs to Class II in the Biopharmaceutics Classification System (BCS) for its high permeability and poor aqueous solubility. The purpose of this study was to improve the solubility and dissolution rate of budesonide using an o/w microemulsion system in order to develop a nasal formulation. Based on the results of the solubility study and pseudo ternary phase diagrams, microemulsions of about 80 nm in mean diameter were formulated using isopropyl myristate and Labrasol$^{(R)}$ as an oil phase and a surfactant, respectively. Solubility of budesonide in the microemulsions increased up to 6.50 mg/mL, which is high enough for a nasal formulation. In vitro release profiles of budesonide significantly increased from the microemulsions compared to that of the budesonide powder. These results suggest that the microemulsions of budesonide could further be developed into a clinically useful nasal formulation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.3
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• pp.201-207
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• 2012

The influence of different dilution procedures on the properties of oil-in-water (O/W) nano-emulsions obtained by dilution of oil-in-ethanol (O/E) microemulsions with water has been studied. The system water/ethanol/nonionic surfactant/silicone oil with ethanol was chosen as model system. The dilution procedures consisted of adding water (or microemulsion) stepwise. By mixing O/E microemulsions into water, nano-emulsions with droplet diameters of 30 nm were obtained. In contrast, by mixing water into O/E microemulsion, emulsions with diameter of 400 nm were obtained The dilution methods were shown to be a key factor determining the properties of the emulsions. There were no change in diameters of nanoemulsion droplets against time, however sizes of droplets in the emulsion with larger droplets were increased with time and the mechanism of unstability was thought to be Ostwald ripening.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.364-371
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• 2007

Effects of continuous oil phase on silver halide nanoparticles were investigated where nanoparticles were prepared using two different types of water-in-oil(W/O) microemulsions containing silver and halide, respectively. Phase behavior experiments for ternary systems containing AOT surfactant, hydrocarbon oil and aqueous solution of an inorganic salt showed that the region of one phase W/O microemulsion was found to be broadened with an increase in the alkyl chain length of a hydrocarbon mainly due to an increase in hydrophilic nature of a surfactant. With the information of phase behavior experiments, silver halide nanoparticles were prepared using different AOT-based microemulsion systems and photomicrographs obtained by transmission electron microscopy indicated that about 10 nm size particles of relatively spherical shape were obtained. It has been found that an increase in alkyl chain length of a hydrocarbon results in a decrease in particle size because of higher intermicellar exchange rate among microemulsion drops. The average particle size was also found to increase with the inorganic salt composition of initial aqueous solution.

• Journal of Pharmaceutical Investigation
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• v.38 no.3
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• pp.171-176
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• 2008

Talniflumate is a nonsteroidal anti-inflammatory drug (NSAID), which has been used treat of rheumatoid diseases, is insoluble in water, therefore it has low bioavailability after oral administration. The purposes of this study were to prepare O/W or W/O microemulsions for solubilization of poorly water soluble drug, talniflumate and to formulate into other dosage form. For this purpose, we made O/W or W/O microemulsion with oil(soybean oil, IPM), surfactant (Cremophor $EL^{(R)}$, Tween 80) and water or propylene glycol and evaluated solubility of talniflumate. The microemulsion systems were very stable and showed transmittance above 95% without flocculation or aggregation. Especially, the solubility of talniflumate in the formulation B-1 containing 18% of isopropyl myristate and 71% of tween 80 was 10 times higher than that of other O/W microemulsions. The addition of propylene glycol and N-methylglutamine to the fomulation B-1 showed excellent capacity on the solubilization of talniflumate and the percentage was almost 2.0%. These results suggest that the microemulsion system may be promising for the solubility improvement of talniflumate.

• 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 the Korean Applied Science and Technology
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• v.20 no.2
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• pp.118-124
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• 2003

Silver nanoparticles was synthesized by the method of W/O microemulsions with AOT (bis(2-ethylhexyl) sodium sulfosuccinate). The nucleation particle growth and aggregation was controlled by the droplet exchange process. The intermicellar exchange reaction is varied by changing the AOT and the $H_2O$ concentration. The synthesized W/O microemulsions was found to give the nanoparticles, which was confirmed by SEM, TEM, particle-size-analyzer, and UV-spectrometer. The most stable particles was obtained at 0.056 mole AOT solution, and the particle size distribution was found in the range from 27 to 31 nm. The mean particle size was reduced by adding Tween 20 significantly, and distribution was found from 14 to 16 nm. And, It's size was reduced by cosurfactants as toluene and benzyl alcohol. In case of toluene and benzyl alcohol, the range of particle size was found 7${\sim}$11 nm and 8${\sim}$12 nm.