• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.153-158
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• 2004

In cosmetics, the saturated lecithin, one of the main surfactants to prepare liposome has been used for its stability but it has been substituting with unsaturated lecithin which has excellent skin affinity and penetration property. So we studied to prepare nano-liposome that size of particles were below than 50nm by unsaturated lecithin. It was important that many factors including solvent such as propylene glycol, pH balance, homogenizing pressure, various cosurfactants and stabilizers to make stable nano-liposome. In our experimental conditions, cosurfactants with stearate class as lipophilic part were more suitable than others for our purpose. But in liposome by saturated lecithin, cosurfactants had negative effect and appropriate amount of oil should be used to be stable. These results indicated that unsaturated lecithin were more suitable than saturated lecithin to prepare nano-liposome.

• Environmental Engineering Research
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• v.23 no.3
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• pp.242-249
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• 2018

The use of palm oil and diesel blended with ethanol, known as a microemulsion biofuel, is gaining attention as an attractive renewable fuel for engines that may serve as a replacement for fossil-based fuels. The microemulsion biofuels can be formulated from the mixture of palm oil and diesel as the oil phase; ethanol as the polar phase; methyl oleate as the surfactant; alkanols as the cosurfactants. This study investigates the influence of the three cosurfactants on fuel consumption and exhaust gas emissions in a direct-injection (DI) diesel engine. The microemulsion biofuels along with neat diesel fuel, palm oil-diesel blends, and biodiesel-diesel blends were tested in a DI diesel engine at two engine loads without engine modification. The formulated microemulsion biofuels increased fuel consumption and gradually reduced the nitrogen oxides ($NO_x$) emissions and exhaust gas temperature; however, there was no significant difference in their carbon monoxide (CO) emissions when compared to those of diesel. Varying the carbon chain length of the cosurfactant demonstrated that the octanol-microemulsion fuel emitted lower CO and $NO_x$ emissions than the butanol- and decanol-microemulsion fuels. Thus, the microemulsion biofuels demonstrated competitive advantages as potential fuels for diesel engines because they reduced exhaust emissions.

• 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.

• Clean Technology
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• v.12 no.1
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• pp.1-9
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• 2006

Aqueous cleaning agents which are considered to be environmental-friendly and promising alternative ones among various industrial cleaning agents were evaluated in this words. In order to formulate aqueous cleaning agents, primary alcohol ethoxylates with 3, 5 and 7 moles of ethylene oxides among nonionic surfactants were selected as main surfactants. And anionic surfactants and alcohols were chosen as their cosurfactants. Builders such as NaOH, KOH, $Na_2CO_3$ and $NaHCO_3$ were also evaluated as additives for improvement of cleaning efficiency of aqueous cleaning agents. The experimental results of cleaning ability tests show that introduction of anionic surfactant TLS as cosurfactant in alcohol ethoxylate-based aqueous solution gives the best cleaning efficiency for removing mixed soil of cutting oil and grease. NaOH and $Na_2CO_3$ are also shown to play an important role for improvement of cleaning efficiency in a aqueous cleaning agent.

• Journal of the Korean Chemical Society
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• v.40 no.1
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• pp.1-10
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• 1996

Gibbs' adsorption isotherms are studied to assay the structural effects of ethylene oxide (EO) and propylene oxide (PO) moieties on the molecular area and the interfacial tension behavior of molecules at the interface. Several industrial alcohols and isomerically pure alcohols, which have a general stucture of C4H9O(EO)m(PO)nH, are examined for their cosurfactant properties. They are high molecular weight alcohols and more surface active than the cosurfactants usually used. Results show that the number and the sequence of EO and PO units significantly affect the molecular areas and the interfacial tension (IFT) behavior of these molecules at the water/oil interface. The following conclusions are drawn from the result: 1) PO is more efficient in lowering the IFT and less effective in adsorption than EO. 2) For molecules having the same molecular weight but different structures, smaller molecules are more efficient in lowering the IFT. 3) When more EO, PO, or both units are added to the same hydrophobe, the molecule become bigger and more efficient in lowering the IFT.

• YAKHAK HOEJI
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• v.55 no.1
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• pp.1-10
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• 2011

Mastic is a bleed resin formed in pistacia lentiscus tree extract form the anacatdiaceae family. Mastic is used as a food ingredient in the Mediteraanean resin, and has been used by local inhabitants as a traditional medicine for relief of upper abdominal discomfort, dyspepsiaand peptic ulcer. Clinically, mastic has been effective in the treatment of benign gastric and duodenal, ulcers, giving symptomatic relief and endoscopically proven healing. In this study, to enhance activiteies of poorly water soluble Mastic with oils, surfactants and cosurfactants and then the mixure was microemulsified in aqueous media under condition of gentle agitation and digestive motility that would be encountered in the gastrointestinal tract. Formulation development and screening were based on phase diagrams and characteristics of resultant microemulsion. For optimum mastic formulation, microemulsions with various ratio (w/w%) of mastics, oils, surfactants and cosurfactants were prepared and their solubility was evaluated by monitoring particles size in their buffer through visual asessment and electrophoretic light scattering spectrophotomerter (ELS). In vitro activity of self microemulsified mastic (SME mastic) was determined by minimum ingibition concentration (MIC) test against a panel of Helicobacter pylori (H. pylori) clinical strains. Additionally, in vivo activity of SME masitc was investigated us mouse infected by CH275 of H. pylori. The mean diameter of SME mastic was less then 100 nm in water and SME mastic was showed similar antiboisis effect compared to tometronidazole, clarithromycin and omeproazole. Consequently, SME mastic would be effective system to exterminate H. pylori. If mastic were dose with combined treatment, mastic might augur well for effect of H. pylori eradication as good remedy.

• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.267-275
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• 2002

A self-microemulsifying drug delivery system (SMEDDS) was developed to increase the dissolution rate, solubility, and ultimately bioavailability of a poorly water soluble drug, lovastatin. SMEDDS was thε mixtures of oils, surfactants, and cosurfactants, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastro-intestinal (GI) tract. Various types of self-emulsifying formulations were prepared using four types of oil (Capryol 90, Lauroglycol 90, Labrafil M 1944 CS and Labrafil M 2125), two surfactants (Cremophor EL and Tween 80), and three cosurfactants (Carbitol, PEG 400 and propylene glycol). Thε efficiency of emulsification was studied using a laser diffraction size analyzer to determine particle size distributions of the resultant emulsions. Optimized formulations selected for bioavailability assessment were Carpryol 90 (40%), Cremophor EL (30%) and Carbitol (30%). SMEDDS containing lovastatin (20 mg and 5 mg) were compared to a conventional lovastatin tablet $(Mevacor^{\circledR},\;20\;mg/tab)$ by the oral administration as prefilled hard gelatin capsules to fasted beagle dogs for in vivo study. The arεa under the serum concentration-time curve from time zero to the last measured time in serum, $AUC_{0{\rightarrow}24h}$, was significantly greater in SMEDDS, suggesting that bioavailability increase 130% and 192% by the SMEDDS, respectively. The self-emulsifying formulations of lovastatin afforded the improvement in absolute oral bioavailability relative to previous data of lovastatin tablet formulation. These data indicate the utility of dispersed self-emulsifying formulations for the oral delivery of lovastatin and potentially other poorly absorbed drugs.

• KSBB Journal
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• v.15 no.6
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• pp.649-657
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• 2000

The factors affecting the back-extraction efficiency of Bovine Serum Albumin (BSA, Mw. 65kDa, pl 4.9) solubilized in an AOT reverse micellar solution, prepared by the injection method, to an excess aqueous phase were investigated. In particular, the effects of pH, the types of salts, alcohols added as cosurfactants, and their concentrations in the aqueous phase were examined. Furthermore, by comparing the CD spectra of the back-extracted BSA and the feed BSA, the structural changes of BSA during the extraction process were determined. The addition of 1:1 salt such as KCl or NaCl to the aqueous phase resulted in almost a 100% extraction to the aqueous phase at a pH higher than its isoelectric point pl. This high efficiency of back-extraction might be due to the change in the interactions between the protein and micellar aggregates driven by the added salt. For 1:2 salts like $CaCl_2$ and $MgCl_2$, BSA was back-extracted with lower than 20% extraction efficiency. Maximum extraction efficiencies were attained at about pH=7 and pH=8 for monovalent and divalent salts, respectively. The addition of alcohols as cosurfactants led to an improvement in monovalent and divalent salts, respectively. From the CD spectra of BSA extracted to the aqueous phase, it was observed that denaturation of BSA was not significant. In certain back-extraction conditions, the extracted BSA showed even higher activity than the feed BSA.

• Polymer(Korea)
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• v.34 no.4
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• pp.333-340
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• 2010

Zaltoprofen, a propionic acid derivative non-steroidal anti-inflammatory drug (NSAID), is known to have powerful inhibitory effects on acute, subacute and chronic inflammation. We developed poly(lactide-co-glycolide)(PLGA) microspheres loaded with zaltoprofen for sustained controlled delivery using an oil-water solvent evaporation methods by varying PLGA molecular weight and cosurfactant contents. Physicochemical properties and morphology of zaltoprofen-loaded PLGA microspheres were investigated by scanning electron microscope, X-ray diffraction and differential scanning calorimeter. The size of microspheres increased with the molecular weight of PLGA and the content of cosurfactants. The increase of PLGA molecular weight and cosurfactant content decreased the porosity of microspheres, subsequently resulting in the slow drug release. The results demonstrated that the adjustment of PLGA molecular weight and the cosurfactant content allowed us to control the drug release profiles of drug-loaded microspheres.

• 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.