• Archives of Pharmacal Research
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• v.9 no.2
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• pp.87-91
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• 1986

In attempt to develop a drug delivery system using serum albumin microspheres, bovine serum albumin microspheres containing antitumar agent. Cytarabine, were prepared. The shape, surface characteristics, size distribution, behavior of in vivo distribution, drug release behavior, and degradation of albumin microsphers in animal liver issue homogenate and proteolytic enzyme were investigated. The shape of albumin microspheres was spherical and the surface was smooth and compact. The size distribution of the albumin microspheres was effected by dispertion forces during emulsification and albumin concentration. Distribution of albumin microspheres after imtravenous administration in rabbit was achieved immediately. In vitro, albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin concentration ratio and size distribution. After drug release test, the morphology of albumin microspheres was not changed. Albumin microsphere matrix was degraded by the animal liver issue homogenate and proteolytic enzyme. The degree of degradation was affected by heating temperature.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.157-160
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• 1992

표면에 여러 가지 기능성기를 가지는 microspheres는 immunoassay, drug delivery system, cell separation등 의용공학분야에 응용이 기대되고 있다. 이들 분야의 응용을 위하여 유화제를 사용하지 않으면서, 기존의 회분식, 반회분식, seed 중합법등의 문제점을 극복한 two stage shot growth technique올 개발하여 여러 가지 기능성기가 표면에 도입된 microspheres를 제조하였으며, 응용의 전단계로서 이들 microspheres에 대한 모델 단백질(BSA)의 흡착실험을 pH, 기능 성기의 종류와 양, BSA농도를 변수로 행하여 최대 흡착량을 보이는 조건을 결정하였다.

• Archives of Pharmacal Research
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• v.8 no.3
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• pp.159-168
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• 1985

In attempt to develop a drug delivery system using serum albumin microspheres, bovine serum albumin microspheres containing antitumor agent, cytarabine, were prepared. The shape, surface characteristics, size distribution, behavior of in vitro distribution, drug release behaior, and degradation of albumin microspheres in animal liver tissue homogenate and proteolytic enzyme were investigated. The shape of albumin microspheres was spherical and the surface was smooth and compact. The size distribution of the albumin microspheres was affected by dispersion forces during emulsification and albumin concentration. Distribution of albumin mirospheres after intravenous administration in rabbit was achieved immediately. In vitro, albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin concentration ratio and size distribution. After drug release test, the morphology of albumin micropheres was not changed. Albumin microsphere matrix was degraded by the rabbit liver tissue homogenate and proteolytic enzyme. The degree of degradation was affected by heating temperature.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.367-375
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• 1995

Ampicillin sodium (AMP-Na) was loaded Into fibrin glue (FG) in two different ways and was tried to achieve sustained release from FG. One was loading of AMP-Na in a simple mixing and the other was loading of bovine serum albumin (BSA) microspheres which contained ANP-Na. In case of simple mixing, the release control of AWP-Na from FG was tried by variation of FBNG concentration, but failed. However, the loading of BSA mlcrosphere containing ANP-Na into FG showed sustained re- lease of AMP-Na, especially when microsphere was crosslinked with glutaraldehyde (tO.9 : 33hr). The maximum adhesive strength of FG showed at concentration of FBWG and thrombin, 5.0 % and 25-50 NIHU/ml, respectively. The concentration of Factor Xlll (0-500 U/1g of FBNG) did not affect the adhesive strength of FG. The optimal incubation time was 60 min. The AMP-Na or BSA microsphere which was loaded into FG had no significant effect on the adhesive strength of FG.

• KSBB Journal
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• v.22 no.3
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• pp.146-150
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• 2007

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] microspheres were prepared using solvent evaporation technique. P(3HB-co-4HB) with 3.9 mol% 4HB was synthesized by fed-batch culture of Ralstonia eutropha. The effects of concentration and type of surfactant (Tween 80, sodium dodecylsulfate, and polyvinyl alcohol), addition of dispersion stabilizer (Acacia), concentration of polymer and model drug (bovine serum albumin) on particle size of the microspheres and their in vitro drug release characteristics were investigated. The average particle size of the microspheres decreased with the addition of dispersion stabilizer and increased with the concentration of surfactant, drug and polymer. Amount of drug release increased with decreasing particle size of the microspheres.

• Journal of Pharmaceutical Investigation
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• v.31 no.4
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• pp.241-256
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• 2001

Alginate microspheres, containing fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) or green fluorescent protein (GFP) were prepared and used as a model drug to develop the oral vaccine delivery system. The alginate microspheres were coated with poly-L-lysine or chitosan. Two methods, w/o-emulsion and spray, were used to prepare alginate microspheres. To optimize preparation conditions, effects of several factors on the particle size and particle morphology of microsphere, and loading efficiency of model antigen were investigated. In both preparation methods, the particle size and the loading efficiency were enhanced when the concentration of sodium alginate increased. In the w/o-emulsion preparation method, as the concentration of Span 80 was increased from 0.5% to 2%, the particle size was decreased, but the loading efficiency was increased. The higher the emulsification speed was, the smaller the particle size and loading efficiency were. The concentration of calcium chloride did not show any effect on the particle size and loading efficiency. In the spray preparation method, the particle size was increased as the nozzle pressure $(from\;1\;kgf/m^2\;to\;3\;kgf/m^2)$ and spray rate was raised. Increasing calcium chloride concentration (<7%) decreased the particle size, in contrast to no effect of calcium chloride concentration on the w/o-emulsion preparation method. Alginate microspheres prepared by two methods were different in the particle size and loading efficiency, the particle size of microspheres prepared by the spray method was about $2-6\;{\mu}m$, larger than that prepared by the w/o emulsion method $(about\;2{\mu}m)$, and the loading efficiency was also higher with spray method. Furthermore, drying process for the microspheres prepared by the spray was simpler and easier, compared with the w/o emulsion preparation. Therefore, the spray method was chosen to prepare alginate microspheres for further experiments. Release pattern of FITC-BSA in alginate microspheres was evaluated in simulated intestinal fluid and PBS (phosphate buffered saline). Dissolution rate of FITC-BSA from alginate/chitosan microsphere was lower than that from alginate microsphere and alginate/poly-L-lysine microsphere. By confocal laser scanning microscope, it was revealed that alginate/FITC-poly-L-lysine microspheres were present in close apposition epithelium of the Peyer's patches of rabbits following inoculation into lumen of intestine, which proved that microspheres could be taken up by Peyer's patch. In conclusion, it is suggested that alginate microsphere prepared by spray method, showing a particle size of & $10\;{\mu}m$ and a high loading efficiency, can be used as a model drug for the development of oral vaccine delivery system.