• Journal of Pharmaceutical Investigation
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• v.21 no.4
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• pp.253-262
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• 1991

Microencapsulation of sodium ascorbate with cellulose acetate phthalate(CAP) by coacervation/ phase separation method were carried out. Various factors affecting microencapsulation, i.e., surfactant concentration. CAP concentration, stirring speed and treatment of spermaceti as a sealing agent were studied. Dissolution rate. particle size distribution, surface feature and stability test were investigated. CAP microcapsules prepared using 0.5% span 80 as a surfactant showed smooth and round surfaces. The release of sodium ascorbate was retarded by microencapsulation with CAP and by sealant treatment with spermaceti. When triturated with sodium bicarbonate, CAP microcapsules were more stable than unencapsulated sodium ascorbate under various RH conditions at $37^{\circ}C$.

• YAKHAK HOEJI
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• v.33 no.5
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• pp.312-318
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• 1989

Microcapsule of Propranolol HCl with Cellulose Acetate Phthalate (CAP) by coacervation-phase separation method was studied. Encapsulation was carried out in the CAP-liquid paraffin-acetone ethanol solvent system. The optimum weight ratio for microencapsulation in the CAP-liquid paraffin-solvent system was 1.32:89.18:9.50 or 1.65:89.42:8.93. The wall thickness of microcapsules increased according to increasing of CAP concentration, but dissolution rate decreased. The dissolution of propranolol-HCl in simulated gastric and intestinal fluid test solution was completed within 3 min., but T50% of propranolol HCl from 10.0% CAP-microcapsules were 390 min. and 210 min. respectively. The released amount from 12.5% CAP-microcapsules was 41.8% within 720 min. in simulatd gastric fluid test solution and T50% of those in simulated intestinal fluid test solution was 250 min.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.5
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• pp.870-876
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• 1996

Microcapsules containing 2,4,4'-trichloro-2-hydroxydiphenyl ether (DP) and perfumes were prepared by the coacervation using poly (vinyl alcohol) and crosslinking agents. Internal phase content, percent releasing of core materials, antimicrobial activities of microcapsules and fabrics treated with them were investigated. The internal content of microcapsules containing perfumes and DP are increased with increasing perfumes. The internal content of cacharia in the microcapsue was higher than that of lemon and its maimum value was 93%. The microcapsules containing perfumes and DP did not release cacharia and lemon at roonl temperature. But the amount of perfumes released from microcapsules were increased with temperature and time of microcapsules containing DP and perfumes showed 100% reduction percentage of bacteria. The size of obstruction of fabrics treated with microcapsule containing DP and perfumes were increased with DP content in microcapsules.

• Clean Technology
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• v.27 no.1
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• pp.55-60
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• 2021

Antibiotics are compounds broadly used to treat patients with infectious diseases and to enhance productivity in agriculture, fisheries, and livestock industries. However, due to the overuse of antibiotics and their low biodegradability, a substantial amount of antibiotics is leaking into the sewer, subsequently resulting in pollution and the emergence of antibiotic-resistant bacteria. This study explores biodegradable serum albumin's potential as an adsorbent to remove antibiotics from water. Serum albumin is a natural blood protein that transports various metabolites and hormones to all tissues' extravascular spaces. While serum albumin is highly water-soluble, it has intrinsic binding sites which readily accommodate ionic, hydrophilic, or hydrophobic molecules, rendering it a good building block for a nano-adsorbent. To induce coacervation, a desolvating agent, ethanol, was added dropwise into the aqueous albumin solution, resulting in dehydration and liquid-liquid phase separation of albumins into albumin nanoparticles within a size range of 150 ~ 170 nm. The addition of glutaraldehyde as a cross-linker improved the size stability and homogeneity of albumin nanoparticles. Adsorption of amoxicillin antibiotics on albumin nanoparticles was dependent upon glutaraldehyde concentration used in desolvation and pH during adsorption. The maximum adsorption capacity measured by spectrophotometry was found to be 12.4 micrograms of amoxicillin per milligram of albumin nanoparticle. These results demonstrate serum albumin's potential as a building block for fabricating a natural nano-adsorbent to remove antibiotics from water.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1277-1281
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• 2011

Making use of chitosan (CS) and ethylenediaminetetraacetic acid (EDTA) as a reaction system, CS-EDTA nanoparticles were synthesized through a facile counterion complex coacervation method. $Ag^+$ could enter porous CS nanoparticles synthesized with this method, allowing Ag nanoparticles within chitosan nanoparticles were synthesized by reducing silver nitrate with chitosan. Because of the noncovalent interaction between CS and EDTA, the EDTA could be easily removed via dialysis against water, and pure core/shell-type Ag/CS nanoparticles could be obtained. The nanoparticles showed higher antibacterial activity toward E. coli than the active precursor Ag nanoparticles and CS.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.20 no.1
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• pp.37-51
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• 1994

Empty cross-linked chitosan microcapsule was prepared by chemical cross-linking reaction using glutaraldehyde(GA). Chitosan bead was also prepared by coacervation method using sodium hydroxide. The technique involves the formation of a chitosan solution in the discontinuous phase of W/O emulsion. The factors influencing the emulsion stability have been examined to establish optimum conditions Chitosan microcapsules were useful for encapsulation of biological materials, and chitosan bead was useful to prepare the biologically active peptide-bound polysaccharide. As a model compound Gly-His-Lys, cell growth factor, was successfully coupled to chitosan bead.

• Food Science of Animal Resources
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• v.37 no.6
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• pp.833-839
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• 2017

In this study, the physicochemical and sensory properties of Gouda cheese supplemented with microcapsules of chili pepper extract were evaluated. Microcapsules of pepper extract were prepared by coacervation technique using gum acacia-gelatin wall and chili pepper oil core. Changes in pH, lactic acid bacteria (LAB) population, and free amino acid (FAA) content after supplementation of Gouda cheese with chili pepper capsules were monitored during ripening. Texture and sensory characteristics of the Gouda cheese ripened for 6 months were evaluated. The supplementation of pepper extract microcapsules (0.5% or 1%, w/w) did not influence the pH values and LAB content of the Gouda cheese (p<0.05) during the ripening period. While the content of total FAA increased with the ripening process in all the cheese groups (p<0.05), no significant difference (p<0.05) in the content of total FAA was observed among the sample groups at each time point. The addition of pepper extract microcapsules (1%, w/w) to Gouda cheese significantly decreased hardness (p<0.05) and negatively affected sensory attributes in terms of taste and texture (p<0.05). The results demonstrated that supplementation with 0.5% pepper extract microcapsules could provide additional bioactive ingredients, along with maintenance of the quality of Gouda cheese.

• YAKHAK HOEJI
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• v.32 no.1
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• pp.26-39
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• 1988

Eudragit $RS^{\circledR}$ polymer was used as a wall material for the microencapsulation of aspirin by a phase separation method from chloroform-cyclohexane system with 5% polyisobutylene (PIB) in cyclohexane, and microcapsules obtained were evaluated by particle size analysis, scanning electron microscopy (SEM), drug release and drug stability test. With PIB as a coacervation inducing agent, smooth and tight microcapsules with less aggregation were obtained. Below 1 : 0.3 core-wall ratio, it was possible to coat individual particle. Variation of production conditions showed that increasing the proportion of wall material, particle size and wall thickness of microcapsules and the concentration of paraffin wax in cyclohexane as a sealant sustained drug release rates effectively. SEM confirmed that larger microcapsules after drug release did not rupture into smaller particles but contained a few small pores on the surface. Aspirin release from Eudragit $RS^{\circledR}$ coated microcapsules was independent of the pH of medium, and the mechanism of drug release from non-sealed and sealed microcapsules appeared to fit Higuchi matrix model kinetics. Aspirin in the mixture of aspirin microcapsules and sodium bicarbonate was by far more stable than that in the mixture of pure aspirin and sodium bicarbonate.

• Journal of Pharmaceutical Investigation
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• v.26 no.4
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• pp.273-280
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• 1996

Chondroitin sulfate/gelatin microspheres containing dexamethasone 21-acetate were prepared by complex coacervation method and their release patterns were examined in vitro. Microspheres prepared with a small amount of crosslinking agent had smooth surface and few pores, but those with a large amount of crosslinking agent were more porous and less spherical. In vitro release patterns were varied by changing polymer/drug weight ratio and amount of crosslinking agent. The release rate of dexamethasone 21-acetate in the presence of collagenase was faster than that in the absence of collagenase. Anti-inflammatory effect of dexamethasone 21-acetate microspheres was more efficient than that of dexamethasone 21-acetate solution in carrageenan-induced arthritis in the rat. On the basis of the above results, we might expect the degradation and drug release rate of these microspheres to be regulated by the degree of crosslinking and the level of enzymes. In patients with severe rheumatoid arthritis who have high concentration of collagenase, more drug would be released from the microspheres. An intra-articular injection therapy of rheumatoid arthritis with desired release kinetics could be developed to enhance patient compliance and therapeutic index.

• Journal of Korea Soil Environment Society
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• v.4 no.3
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• pp.17-24
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• 1999

The effects of hydrophobic chain length and its structure of nonionic surfactants on surfactant adsorption and contaminated diesel removal were studied in kaolin soil. Hydrocarbon chain length and double bond in hydrophobic tail group of nonionic surfactants affected surfactant adsorption and diesel removal efficiency from kaolin soil. The degrees of surfactant adsorption and diesel removal were closely related each other. Among nonionic surfactants we studied, surfactants with shorter hydrophobic chain length and higher HLB value showed lower degree of adsorption and higher efficiency of diesel removal. The existence of unsaturated carbons in the structure of hydrophobic chain enhanced diesel removal by reducing surfactant adsorption to kaolin soil. The best diesel removal was obtained after adsorption saturation was reached. If surfactant concentration was higher than a critical value, diesel removal was reduced probably because of precipitation. liquid crystal formation, or coacervation of surfactants at high concentration.