• YAKHAK HOEJI
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• v.31 no.3
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• pp.182-188
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• 1987

Simple coacervation of bovine serum albumin was studied to prepare biodegradable microacapsule. Albumin microcapsules were prepared by using acrylonitrilestyrene polymer (M-80) resin beads and sulfamethoxydiazine as the core materials. The albumin to beads ratio was found to be 1:2.3 and the albumin to sulfamethoxydiazine ratio to be 1:2.9. The 50% release times (T$_{50%}$) of sulfamethoxydiazine and microencapsulated sulfamethoxydiazine were 6 min. and 73 min., respectively. The surface appearance of the microcapsule collected after release experiment was not different from those of the original microcapsule. In addition to slowing release of drug the microencapsulation process masked characteristic bitter taste of sulfamethoxydiazine.

• YAKHAK HOEJI
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• v.33 no.3
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• pp.191-202
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• 1989

Indomethacin, a non-steroidal antiinflammatory drug inducing gastric irritation, was microencapsulated using pectin-gelatin complex coacervation method. Optimum conditions for microencapsulation and dissolution characteristics of the microcapsules were studied. The optimum pH and pectin-gelatin ratio for microencapsulation were 3.8 and 1:2 respectively. As concentration of colloid solution increased, wall thickness of microcapsules were increased. The dissolution rate of Indomethacin-pectin-gelatin microcapsules prepared by 1.5% and 2% colloid solution were similar but slower than that of Indomethacin-pectin-gelatin microcapsules prepared by 1% colloid solution. The 50% release time ($T_{50%}$) of Indomethacin-pectin-gelatin microcapsules prepared by 1%, 1.5% and 2% colloid solutions were 3 min, 5 min, and 6 min respectively while that of Indomethacin powder was 50 min.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.9_10
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• pp.1172-1177
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• 2003

Microcapsules were prepared by complex coacervation between gelatin and gum arabic. The object of this work is evaluation of the effect of jelly strength, hardening agent on the particle size distribution, surface morphology and DSC. It was found that the 300bloom jelly strength caused microcapsules' size larger. When the amount of hardening agent increased, the particle mean diameter was larger. The amount of hardening agent was determined to be 10m1 for getting suitable size to finish the fabric.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.139-144
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• 1993

Microencapsulation of acyclovir, an effective antiviral agent which acts as a specific inhibitor of herpes DNA polymerase, by carbopol-gelatin complex coacervation has been carried out to develop an oral controlled release preparation, which could improve the absorption characteristics in GI tract. After dissolving carbopol and gelatin separately in distilled water at $40^{\circ}C$, gelatin solution was mixed with carbopol solution while stirring at the same temperature. The pH of the mixture was lowered gradually by dropwise addition of 10% HCI with continuous stirring, and then, at pH 3.5, positively charged gelatin molecules were attracted to negatively charged carbopol. These coacervation processes were observed by optical microscopy during preparation. Plasma concentrations of acyclovir in rats after an oral administration of microcapsule suspension were assayed by HPLC, and pharmacokinetic parameters were calculated based on the model-independent analyses. Two standard formulations, oral solution and intravenous bolus injection, were used as references to compare the bioavailability. It has been revealed that $C_{max}$, $T_{max}$, and MRT of microcapsule suspension were greater than those of oral solution, which results in about two-fold increases in bioavailability. Therefore, in conclusion, the carbopol-gelatin microcapsule of acyclovir might be evaluated as an effective oral controlled release preparation which could increase the bioavailability of acyclovir.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.273-284
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• 2001

A series of microcapsule were synthesized by using several PCM(Phase Change Material) as a core material and gelatin/arabic gum, melamine/formaldehyde as a shell material. Coacervation technique and in situ polymerization were adopted in synthesizing microcapsules. In the microencapsulation by coacervation, tetradecane and octadecane were used as core materials. In the microencapsulation by situ polymerization tetradecane, pentadecane, hexadecane, heptadecane, octadecane, and nonadecane were used as core material. The synthesized microcapsule was examined to observe the shape of the microcapsule. The particle size analysis was performed by particle size analyzer. The thermal properties(e.g. melting point, heat of melting, crystallization temperature, heat of crystallization, differences between melting point and crystallization temperature) were obtained by DSC(Differential Scanning Calorimeter). The stirring rate effect was investigated during the microencapsulation. It was found that with increasing the stirring rate much smaller microcapule was produced. However, this did not necessarily lead to formation of spherical microcapsule.

• Food Engineering Progress
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• v.21 no.3
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• pp.215-224
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• 2017

Resveratrol was incorporated into various combinations of single- and double-layer nanoemulsions, prepared by self-assembly emulsification and complex coacervation with chitosan, alginate, and ${\beta}$-cyclodextrin, respectively. Resveratrol nanoemulsions were composed of medium-chain trigacylglycerols (MCTs), $Tween^{(R)}$ 80, water, chitosan, alginate, and ${\beta}$-cyclodextrin. The corresponding mixtures were formulated for the purpose of being used as a nutraceutical delivery system. Resveratrol nanoemulsions were obtained with particle sizes of 10-800 nm, with the size variation dependent on the emulsification parameters including the ratio of aqueous phase and surfactant ratio. Resveratrol nanoemulsions were characterized by evaluating particle size, zeta-potential value, stability, and release rate. There were no significant changes in particle size and zeta-potential value of resveratrol nanoemulsions during storage for 28 days at $25^{\circ}C$. The stability of resveratrol in the double-layer nanoemulsions complexed with chitosan or ${\beta}$-cyclodextrin was higher, compared with the single-layer nanoemulsions.

• Proceedings of the Korean Fiber Society Conference
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• 1992.06b
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• pp.116-117
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• 1992

• Journal of Life Science
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• v.6 no.2
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• pp.129-134
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• 1996

The development of fish feed is essential to aquaculture. Recently, yeast, dhlorella and plankton have been studied and development as the feed of the fry fishes, But, these biological feeds cause the nutritional unbalance to fry fishes, rotifer or artemia. Therefore, to solve these problems, microcapsules with micron sizes were prepared for enhancing the nutritional values of artemia and rotifer which are used as the feed of fry fishes. Microparticle oil capsules were prepared by the complex coacervation technique. The method to make the optimal size of microcapsule which the artemia and rotifer can be easily taken was wvaluated. The size of oil microcapsule in the range of 5-70$\mu$m was obtained by the agitation conditions during coacervation. Capsule size and size distribution were dependent on the agitation speed and agitation time, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.914-916
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• 2009

Using gelatin and acacia as wall and electronic ink as core substance, microcapsules were prepared by complex coacervation to fabricate a flexible electronic paper display. In order to obtain the microcapsules in a narrow dispersed distribution, we focus on the interfacial tension between the hydrophobic electrophoretic ink and an aqueous polyelectrolyte solution, through controlling sodium dodecyl sulphate (SDS) concentration and stirring rate. The existence of anionic surfactant of SDS not only decreases the droplet diameters, but also reduces the diameter size distribution. And, as the stirring rate is increased, the average size of microcapsule is also decreased.

• YAKHAK HOEJI
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• v.28 no.4
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• pp.223-229
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• 1984

Microcapsules of indomethacin were prepared by the complex coacervation technique using gelatin-gum arabic as the wall-forming material. The effects of varying drug-to-matrix ratios and formalization time, and hydroxy propyl cellulose (HPC) added on the release of drug from microcapsules were studied. As the amount of wall-forming material increased, the drug content in the microcapsules decreased and the release of drug from microcapsules was retarded. The drug content was lower in the HPC added microcapsules than that in the microcapsules was retarded. The drug content was lower in the HPC added microcapsules than that in the microcapsules without HPC and the microcapsules with 1:4 drug-to-matrix ratio showed the slowest release. The release rate of the drug from microcapsules with 1:2 drug-to-matrix was delayed according to the increase of formalization time and the microcapsules formalized for 24hr showed ratio the most retardation.