• Title/Summary/Keyword: microsphere

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pH-Sensitive Curdlan Acetate Microspheres를 이용한 Indomethacin의 방출 특성

  • Lee, Chang-Mun;Lee, Yeong-Jin;Lee, Gi-Yeong;Choe, Chun-Sun
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.739-742
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    • 2003
  • Curdlan acetate was prepared from hydrophilic curdlan by chemical modification and it was used for pH-sensitive drug delivery system. Curdlan acetate microspheres were prepared by the solvent evaporation method. The size of the curdlan acetate microspheres was below $200\;{\mu}m$. The drug loading efficiency of microspheres was approximately 58.44%. In the swelling test, curdlan acetate microspheres were showed pH-sensitive behavior. The swelling capacity of microspheres at pH 7.4 was much greater than at pH 1.4. Also, Release rate of indomethacin (IND) at pH 7.4 from curdlan acetate microspheres was faster than that at pH 1.4. A pH-sensitive drug release pattern was due to the disintegrating after swelling.

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Preparation and Characterization of Poly(D,L-lactic acid) Microspheres Containing Alprazolam (Alprazolam함유 poly(D,L-lactic acid) Microsphere의 제조 및 평가)

  • Yong, Chul-Soon;Kwon, Mi-Ra;Park, Sae-Hae;Oh, Doo-Man
    • Journal of Pharmaceutical Investigation
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    • v.26 no.1
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    • pp.13-22
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    • 1996
  • Poly(D,L-lactic acid) (PLA) microspheres containing alprazolam(APZ) 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 APZ to PLA, PLA concentration in the dispersed phase and stirring rate. Rod-like APZ 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 APZ for long-acting injectable delivery system in vitro, which would aid in predicting in vitro release profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres.

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Assessment of Biodegradability of Polymeric Microspheres in vivo: Poly(DL-lactic acid), poly(L-lactic acid) and poly(DL-lactide-co-glycolid) microspheres

  • Oh, In-Joon;Oh, Jhin-Yee;Lee, Kang-Choon
    • Archives of Pharmacal Research
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    • v.16 no.4
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    • pp.312-317
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    • 1993
  • To confirm a new evaluation tedhnique for biodegradability of biopolymer microsphers in vivo condition, magnetic microsphere sytem was adopted for tracing the microspheres injected and lodged in micr. Microsphers of poly(DL-lactic acid), poly(L-alctic acid) and poly(DL-lactide-coglycolide)(PLGA) were prepared by solvent-extraction method and their organ distribution and biodegradation in mice was examined. Magnetic microspheres lodged in mice organs were recollected from the homogenates of mice organs with a constant flow magnetic separation apparatus. Recollected microspheres were observed by scanning electron microscopy and also were assayed for their magnetite ocntent by atomic absorption spectrophotometry to evaluate the biodegradability of polymeric microspheres. This method seems to be practical and simple to estimate the biodegradability of biopolymers over the conventional methods.

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Synthesis of TiO2 Hollow Microspheres Using Ionic Liquids (이온성액체를 이용한 이산화티타늄 미세중공체 합성)

  • Hong, Kiwon;Yoo, Kyesang
    • Applied Chemistry for Engineering
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    • v.22 no.3
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    • pp.340-342
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    • 2011
  • $TiO_2$ hollow microsphere was simply synthesized using various ionic liquids. Shapes and sizes of hollow microspheres were significantly different with the composition of ionic liquids. This is mainly attributed to the interaction between the organic solvent and the ionic liquid at the interface leading to the formation of micropsphere. Among the ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate was the most effective to synthesize the hollow microsphere.