• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.38.2-38.2
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• 2009

Regeration of natural tissuesor to create biological substitutes for defective or lost tissues and organs through the use of cells. In addition to cells and their porous, drugs are required to promote tissue regeneration. Therefore, the present studies were prepared using simvastatim loaded porous poly(lactide-co-glycolide) (PLGA) by double emulsion solvent evaporation water-in-oil-in-water technique (W/O/W) as drug delivery system strategies for injuring tissue. The resulting microspheres were evaluated for morphology, particle size, encapsulation efficiency, degradation of PLGA microspheres in vitro drug release and in vitro cell viability. Scanning electronic microscopic (SEM) showed that the porosities of the particles was changed by experimental conditions and cultured cells were attached well on porous microspheres surface. The X-ray diffraction (XRD) and differential scanning calometry (DSC) analysis indicate thatsimvastatim was highly dipersed in the microsphere at amorphousstate.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.655-659
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• 2003

Solid lipid nanoparticle (SLN) system has been attracted increasing attention during last few years as a potential drug delivery carrier However, the SLN have disadvantage of low encapsulation efficiency for hydrophilic drug. In this study, for increase it's encapsulation efficiency, we prepared the $Eudragit^{\circledR}$ L100-55 (eudragit) coated SLN(E-SLN) based on solvent evaporation method and melt dispersion technique, and analyzed their physicochemical properties in terms of particle size, morphology, and encapsulation efficiency. As a result, they have a ${\pm}150$ nm particle size, spherical shape, and $10^{\sim}25$ % loading efficiency. SLN consists of coconut oil as core material, ascorbic acid and okyong-san as hydrophilic drug.

• Particle and aerosol research
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• v.6 no.2
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• pp.61-67
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• 2010

In this paper, we describe a new method to form polymer thin films, in which carbon nanotubes (CNTs) are homogeneously distributed so that they can strengthen the mechanical property of resulting polymer film. To do so, we first homogeneously mixed CNTs with polymer in a DMF solvent. With the assistance of ultrasonic nebulizer, the polymer/CNT solution was then aerosolized into micro-sized droplets and finally turned into solidified polymer/CNT composite particles by gas-phase drying process. As the results of SEM and TEM analysis, CNTs were found to be homogeneously immobilized in the polymer matrix particles due to rapid drying process in the gas phase. For comparison purpose, (i) the polymer/CNTs composite particles prepared by aerosol processing method and (ii) polymer/CNTs sheets prepared by simple solution-evaporation method were employed to form polymer/CNTs composite thin films using a hot press. As the result, the aerosol processing of composite particles was found to be a much more effective method to form homogeneously distributed-CNTs in the polymer matrix thin film.

• Journal of Life Science
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• v.12 no.6
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• pp.745-751
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• 2002

Several bacterial strains producing biosurfactants were isolated from polluted marine and soil by oil. One of the strains named LSC11 showed strong production activity of biosurfactants. This strain was identified as a Bacillus sp. LSC11 based on the morphological, biochemical, and physiological characteristics. The biosurfactant, produced by the strain, emulsified crude oil, vegetable oil, and hydrocarbons. The surface tension of the culture broth of Bacillus sp. LSC11 decreased to 32 mN/m. The crude biosurfactant was obtained from the culture broth by acid precipitation, freeze drying, solvent extraction, and evaporation. The emulsifying activity of the biosurfactant showed better than the chemically synthesized surfactant (SDS, Span40, Span 85). The biosurfactants had strong properties as an emulsifying agent and as an emulsion-stabilizing agent.

• Polymer(Korea)
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• v.26 no.3
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• pp.360-366
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• 2002

The electrospinning of polyacrylonitrile dissolved in N,N-dimethyl formamide (DMF) successfully produced nano-scale fibers. The processing parameters such as charged voltage, velocity of collected roller, and tip-to-collector distance (TCD) , affected the ultimate fiber size. At TCD of 5 cm, the average tiber diameter increased with increasing charged voltage because of the more aggregation between fibers due to the remaining DMF solvent on the fiber surface. But, at TCD of 9 cm, the average fiber diameter decreased as the charged voltage was increased because of complete evaporation of DMF. Also, the fiber diameter decreased with increasing the velocity of collected roller. Cross direction width (CWD) of nonwoven mat increased with decreasing the charged voltage and with increasing TCD.

• Applied Biological Chemistry
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• v.2
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• pp.36-39
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• 1961

It has been ascertained that S-(1, 2-dichlorovinyl) L-cysteine (DCVC) is probably the toxic component in the trichloro-ethylene extracted soybean oil meal on the bovine. For the study of the metabolites of DCVC, the components with radioactive $S^{35}$-in the urine of the calf, to which $S^{35}$-DCVC was administrated, were separated using of cellulose powder with propanol-water (70:30 V/V) which is easily removable by evaporation. As the results followings were obtained: Peak 1, which shows fractions containing single $S^{35}$-radioactive components, whose Rf is 0.815 Peak 2, which shows fractions containing jingle $S^{35}$-radioactive component, whose Rf is 0.447 Peak 3, which shows fractions containing both $S^{35}$-radioactive components whose Rfs are 0.090 and 0.171 Peak 4, which shows fractions containing single $S^{35}$-radioactive component, whose Rf is 0.142. Peak 5, which shows fractions containing single $S^{35}$-radioactive component, whose Rf is 0.084. Besides these, two of small peak were obtained. Although, the resolving power of the cellulose powder column is not sufficient, it is applicable for the study of the components of metabolytes of DCVC conveniently with the rest of removable solvent easily. Also the components with radioactive $S^{35}$ in the feces of the calf were separated using citrate buffer gradient system of Moore and stein. As the results; three $S^{35}$-radioactive components were separated.

• Journal of Pharmaceutical Investigation
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• v.22 no.4
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• pp.323-326
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• 1992

$Poly({\varepsilon}-carbobenzoxy\;L-lysine)/poly(ethylene oxide)/poly({\varepsilon}-carbobenzoxy\;L-lysine)$ (LEL) block copolymers containing $poly({\varepsilon}-carbobenzoxy\;L-lysine)$ (PCLL) as the A component and poly(ethylene oxide) (PEO) as the B component were investigated as drug delivery matrix. PCLL homopolymer and LEL block copolymer microspheres containing anticancer drug, cytarabine, were prepared by a solvent evaporation process and the release patterns of cytarabine from the microspheres were investigated in vitro. The size of PCLL homopolymer and LEL block copolymer microspheres was ranged from $0.2\;{\mu}m$ to $1\;{\mu}m$ in diameter and the shape of the microspheres was almost round. The release pattern of cytarabine from the block copolymer microspheres was dependent on the mole % of PEO of the block copolymers.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.468-471
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• 2013

In this paper, we analyzed the effects of the number of TIPS-pentacene droplets and also the substrate temperature on the performance of OTFTs. As the number of the droplets increased, the mobility increased and reached the peak value and then reduced at the all temperatures. The peak mobility was $0.14{\pm}0.03cm^2/V{\cdot}sec$ at 3 droplets and $41^{\circ}C$, $0.19{\pm}0.02cm^2/V{\cdot}sec$ at 4 droplets and $46^{\circ}C$, and $0.35{\pm}0.10cm^2/V{\cdot}sec$ at 7 droplets and $51^{\circ}C$. The reason of existence of peak mobility can be found in matching the evaporation of solvent with the velocity of crystal formation. When two parameters were properly matched, the mobility produced the highest.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.295-301
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• 1997

Nitrendipine, a slightly soluble calcium channel blocking agent forms a solid dispersion system with $hydroxypropyl-{\beta}-cyclodextrin$, which exhibits better dissolution characteristics than the uncomplexed drug. The dissolution rate of nitrendipine was markedly increased in solid dispersion system in pharmacopeial disintegration media at pH 1.2 and pH 6.8. Four different dosage forms of nitrendipine were administered to rats: (a) nitrendipine in the solution of PEG 400; (b) nitrendipine solid dispersion system with $hydroxypropyl-{\beta}-cyclodextrin$ in a molar ratio of 1:2 by solvent evaporation method and administered in capsule form; (c) physical mixture of nitrendipine with $hydroxypropyl-{\beta}-cyclodextrin$ in a molar ratio of 1:2 and administered in capsule form; (d) nitrendipine alone administered in capsule form. Relative bioavailability after the oral administration of various dosage forms to rats with a dose of 10 mg/kg equivalent to nitrendipine was compared with that of nitrendipine in the solution of PEG 400. The AUC of solid dispersion was significantly bigger than that of nitrendipine powder. $T_{max}$ of solid dispersion was significantly shorter and $C_{max}$ was higher than that of nitrendipine powder. These results indicate that the bioavailability of nitrendipine could be improved markedly by inclusion complexation. An interesting correlation also appears to exist between the in vitro dissolution data and the area under the plasma concentration-time curves.

• Journal of Pharmaceutical Investigation
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• v.36 no.3
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• pp.175-184
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• 2006

Poly(D,L-lacic acid)(PLA) microshperes containing loazepam were prepared by a solvent-emulsion evaporation method and their release patterns were investigated in vitro. Various batches of microspheres with different size and drug content were obtained by changing the ratio of lorazepam to PLA, PLA concentration in the dispersed phase and stirring rate. Rod-like lorazepam crystals on microsphere surface, which were released rapidly and could act as a loading dose, were observed with increasing drug content. The release rate was increased with increase in drug contents and decrease in the molecular weight of PLA. The release rate of lorazepam for long-acting injectable delivery system in vitro, which would aid in Predicting in vivo release Profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres.