• 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 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.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.607-614
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• 1997

Flurbiprofen- and flurbiprofen axetil-loaded microemulsions composed of soybean oil, poloxamer 407, glycerine and water were prepared by generator-type homgenizer and ultrasoni c probe system. The particle size of microemulsions was measured by the dynamic light scattering method. The pharmacokinetics and organ distribution of flurbiprofen were investigated after intravenous injection of flurbiprofen solution, flurbiprofen-loaded microemulsion and flurbiprofen axetil-loaded microemulsions equivalent to 10mg/kg of flurbiprofen to rats. Blood samples were collected from the anterior ciliary artery of rats for 24hr, and flurbiprofen in plasma and organs was analyzed by HPLC. Stable microemulsions were prepared. Even though there is a little change in droplet size just after the preparation, no creaming and no separation were occured during the storage period for 6 months at 4, 21, 37 and 45$^{\circ}C$. Pharmacokinetic parameters and organ distribution of flurbiprofen after intravenous injection of flurbiprofen- and flurbiprofen axetil-loaded microemulsions emulsified with poloxamer 407 were not significantly different from those of commercial lipid microemulsion emulsified with lecithin. Therefore, it is concluded that flurbiprofen- and flurbiprofen axetil-loaded microemulsion prepared with poloxamer 407 could be used as a parenteral formulation.

• 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.

• Clean Technology
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• v.10 no.4
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• pp.221-228
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• 2004

Ethoxylated Nonyl Phenol Series (NP-series), nonionic surfactants, were applied for forming microemulsions in supercritical $CO_2$. Measurement results of the solubility in supercritical $CO_2$ are in the following; NP-series were high soluble in carbon dioxide in spite of the fact that those were not $CO_2$-philic surfactants traditionally well known. Water in $CO_2$ microemulsions were also formed stably. A complexation of hydrophilic lengths for $CO_2$-philic parts of NP-Series surfactants was optimized by NP-4 surfactant(N=4) for forming the microemulsions through the experiments. Formation of microemulsions was confirmed by measuring the UV-Visible spectrum through a spectroscopic method and existence of water in the microemulsions was confirmed as well. In order to apply it for a metal surface treatment or electroplating, an experiment for forming acid(organic, inorganic) solution in $CO_2$ microemulsions was carried out. Ionic surfactant in the reaction to an acid solution became unstable to form microemulsions, however, nonionic surfactant was formed stably in the reaction. Results of the study will be utilized for expanding the application scope of supercritical $CO_2$ which is an environmental-friendly solvent.

• 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.

• KSBB Journal
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• v.7 no.3
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• pp.161-165
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• 1992

Water-insoluble sitosterol was biotransformed to AD(4-androstene-3, 17-dione) and ADD(1, 4-androstadiene-3, 17-dione) with crosslinked Mycobacteria sp. NRRL B-3683 in microemulsions. The Mycobacteria activity depended on the kinds of surfactants and water content. The activity was very high in cationic microemulsion (CTAB-buthanol-cyclohexane-water) and five times higher than that of buffer, but it showed a very low activity in anionic microemulsion. The Mycobacteria activity was increased as increasing as increasing water contents and in the microemulsion containing 20% water was doubled in the same microumulsion containing 5% water. We suggest that microemulsion is effective reaction medium for Mycobacteria bioconversion.

• 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.

• Archives of Pharmacal Research
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• v.28 no.9
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• pp.1097-1102
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• 2005

An O/W microemulsion system was developed to enhance the skin permeability of ace-clofenac. Of the oils studied, Labrafil? M 1944 CS was chosen as the oil phase: of the microemulson, as it showed a good solubilizing capacity. Pseudo-ternary phase diagrams were constructed to obtain the concentration range of oil, surfactant, Cremophor ELP, and co-surfactant, ethanol, for micoemulsion formation. Eight different formulations with various values of oil of $6-30\%$, water of $0-80\%$, and the mixture of surfactant and co-surfactant (at the ratio of 2) of $14-70\%$. The in vitro transdermal permeability of aceclofenac from the microemulsions was evaluated using Franz diffusion cells mounted with rat skin. The level of aceclofenac permeated was analyzed by HPLC and the droplet size' of the microemulsions was characterized using a Zetasizer Nano-ZS. Terpenes were added to the microemulsions at a level of $5\%$, and their effects on the skin permeation of aceclofenac were investigated. The mean diameters of the microemulsions ranged between approximately $10\~100nm$, and the skin permeability of the aceclofenac incorporated into the microemulsion systems was 5-fold higher than that of the ethanol vehicle. Of the various terpenes added, limonene had the best enhancing ability. These results indicate that the microemulsion pystem studied is a promising tool for the percutaneous delivery of aceclofenac.

• Journal of the Korean Applied Science and Technology
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• v.21 no.1
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• pp.17-23
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• 2004

Silver bromide particles from 50 to 200${\AA}$ in diameter are prepared by mixing two microemulsions contaning the precursor salts $AgNO_3$ and KBr. The microemulsions are composed of AOT(bis(2-ethylhexyl) sodium sulfosuccinate), n-heptane and water. The particle diameters are measured on photomicrographs obtained by transmission electron microscopy. The size of the particles is generally larger than that of the water cores. The influence of both the concentration of precursor salts in the water cores of the microemulsoin and the size of these water cores on the size of the particles has been studied.