• Title/Summary/Keyword: release characteristics

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Preparation and Dissolution Characteristics of Sustained Release Granules Containing Indapamide (인다파마이드가 함유된 서방형 과립의 제조 및 용출 특성)

  • Park, Ji-Seon;Seo, Hui;Kim, Byung-Jin;Jeong, Sang-Young;Shin, Byung-Cheol;Yuk, Sun-Hong;Hwang, Sung-Joo;Cho, Sun-Hang
    • Journal of Pharmaceutical Investigation
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    • v.38 no.2
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    • pp.105-110
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    • 2008
  • Indapamide (4-chloro-N-(2-methyl-1-indolinyl)-3-sulfamoyl-benz-amide) is an oral antihypertensive diuretic agent indicated for the treatment of hypertensive. The diuretic and natriuretic effects are mainly due to the structure of o-chlorobenzenesulfonamide. The objective of this study was to formulate sustained release indapamide granules and assess their formulation variables. Granules were prepared by fluid bed coating method and consist of drug layer and membrane layer. The granules were coated with HPC and ethyl cellulose along with plasticizer dibuthyl sebacate. The release of indapamide depended on the type of Eudragit such as RS and NE 30 D used in the formulation controlled release layer. These results obtained clearly suggest that the sustained release oral delivery system for indapamide could be designed with satisfying drug release profile approved.

A Study on the Combustion Characteristics of Synthetic Insulation for Building (건축용 합성 단열재의 연소특성에 관한 연구)

  • Kwon, Hyun-Seok;Lee, Si-Young;Kim, Jong-Buk;Yoon, Myoung-Oh
    • Fire Science and Engineering
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    • v.32 no.2
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    • pp.30-37
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    • 2018
  • This study is an analysis of combustion characteristics of synthetic insulation materials such as houses and warehouses. Using combustion cone calorimeter and SEM, the researching has experimented combustion characteristics of four kinds of materials such as flame retardant styrofoam, general styrofoam, urethane and gypsum board. And analyzed. As a result of the test, the ignition time (TTI) for the thermal insulation material was found at 27 s~43 s, and the flame retardant styrofoam was ignited at the lowest TTI at 27 s and disappears at 28 s. In addition, the maximum heat release rate (peak HRR) and average heat release rate (mean HRR) of each material were expressed in the following order: urethane> flame retardant styrofoam> styrofoam> gypsum board. Also, the total smoke release ($m^2/m^2$) was the largest at $30.798m^2/m^2$ in flame-retardant styrofoam. The general CO concentration of styrofoam was 0.275 kg/kg and the emission concentration was 12.807 kg/kg. The residues showed the highest 0.029 g in the gypsum board among the above materials.

Analysis on Multi-Components of Neurotransmitter Release in Response to Light of Retinal ON-Type Bipolar Cells (망막 ON형 쌍극세포의 광응답에 따른 다중성분의 전달물질 방출에 관한 해석)

  • Jung, Nam-Chae
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.4
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    • pp.222-230
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    • 2013
  • Retinal bipolar cells according to the light stimulus respond to potential slowly, emit neurotransmitter release(glutamine acid) to depend on membrane potential. In this paper, the several physiological information on neurotransmitter release mechanism in the presynaptic terminal of the ON-type bipolar cells are incorporated into the formula model. The source of fast components and slow components of neurotransmitter release was arranged in parallel, this model was able to reproduce the membrane potential and intracellular $Ca^{2+}$ concentration dependence of neurotransmitter release faithfully. In addition, because the fast releasable components of neurotransmitter was represented by the membrane potential dependence of trapezoid type, whereas the slow releasable components was represented by the membrane potential dependence of a bell type, $Ca^{2+}$ concentration rise in intracellular is suppressed by $Ca^{2+}$ buffer to reduce slow releasable components, it was confirmed that the membrane potential dependence of neurotransmitter release was characteristics of a trapezoid type. And, in the light response of ON type bipolar cell, the result of the simulation of the neurotransmitter release caused by the components of transient and persistent was that the start of light response occurred the fast release of neurotransmitter, it was confirmed that the transient component and persistent component of the light response occurred the slow release. It was confirmed that the later of persistent component of the light response occurred due to the continuous release by synaptic vesicle supplemented from the storage pool.

Preparation and release characteristics of PVP-based solid dispersion capsules containing solubilizers

  • Cao, Qing-Ri;Kim, Tae-Wan;Choi, Choon-Young;Lee, Beom-Jin
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.412.1-412.1
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    • 2002
  • Purpose. To prepare PVP-based solid dispersions containing lovastatin (LOS) and solubilizers (sodium lauryl sulfate. Tween80. oleic acid) to enhance dissolution of practically insoluble LOS. Methods. Solid dispersions containing LOS were prepared by dissolving two different organic solvent systems (acetone/ethanol or acetonitrile/ethanol). Results. The stickiness and flowability of solid dispersion powders were dependent on the composition and ratio of the solubilizers. (omitted)

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Combustion Characteristics and Thermal Properties for Wood Flour-High Density Polyethylene Composites (목분-고밀도폴리에틸렌 복합체의 연소성 및 열적특성)

  • Shin, Baeg-Woo;Chung, Kook-Sam
    • Fire Science and Engineering
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    • v.26 no.1
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    • pp.89-95
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    • 2012
  • In this study, we were manufactured wood flour-HDPE composites by modular co-rotating twin screw extruder with L/D ratio of 42. We was measured cone calorimeter test and thermogravimetric analysis (TGA) to find the combustion characteristics and thermal properties for wood flour-HDPE composites. We then evaluated the effect of three additive-type flame retardants on fire resistance performance. The cone calorimeter test showed that the heat release rate (HRR) of untreated composites was the highest Peak HRR ($446.6kW/m^2$) as well as Mean HRR ($185.5kW/m^2$). From the TGA, it was shown that composites added flame retardants began early thermal decomposition and improved thermal stability.

The Characteristics on the Engine Performance for Variation of Fuel Injection Timing in DI Diesel Engine Using Biodiesel(II) (바이오디젤 사용과 연료분사시기 변화에 따른 DI 디젤기관 성능 특성(II))

  • Jang, Se-Ho
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.25-32
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    • 2013
  • Biodiesel is technically competitive with it and offers technical advantages over conventional petroleum diesel fuel. Biodiesel is an environment friendly alternative liquid fuel that can be used in any diesel engine without modification. In this study, (dP/dCA)max and heat release, emission characteristics with different fuel injection timings are compared between diesel fuel and biodiesel in the D.I. diesel engine with T/C. The engine was operated at five different fuel injection timings from BTDC 6deg to 14deg at 2deg intervals and with four different loads at engine speed of 1800rpm. The experiments in a test engine showed that ranges between low and high of (dP/dCA)max got narrower, as the engine load increased, BD blend rate increased, and fuel injection timing was delayed. Cumulative heat release increased with the advanced fuel injection timing. NOX emissions decreased with the delays of fuel injection timing.

The Surface Characteristics of Biomaterials Fixed with a Hydrophilic Membrane by Photochemical Reaction (광화학적 방법으로 친수성막이 고정화된 생체 재료의 표면특성 분석)

  • Kim, H.J.;Jeon, S.M.;Lee, K.B.;Min, B.G.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.11-15
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    • 1997
  • We used the photoreactive poly(allylamie) (PPA) as the hydrophilic membrane to control the release of drug from polyurethane(PU). PPA was covalently bonded onto PU surface through the highly reactive nitrene intermediate upon UV light irradiation $(3.3mW/cm^2)$ at 254nm for 5min. Thus the release rate of rifampicin from PU surface was controlled. To know the characteristics of PU surface bonded with PPA, we measured the ATR-FTIR, ESCA, Static Contact Angle and SEM. From these, we suggest that PPA as a hydrophilic membrane is enable to control the release rate of a hydrophobic drug from polymer without the change of bulk property.

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A Study on Fire Behavior of Combustibles in a Residential Building (주택 가연물의 연소 특성에 관한 연구)

  • Lee, Sung-Ryong;Youk, Keun-Hwan
    • Fire Science and Engineering
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    • v.23 no.4
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    • pp.25-31
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    • 2009
  • With rapid growths of economy and technology, structures and forms of buildings have been diversified and complicated. Buildings also have become higher and larger than ever before. As a result, more people use a building and more combustibles exist in the building. Without understanding of combustion characteristics and the establishment of a fire safety plan in case of a residential fire, it is expected great loss of lives and properties. In this study, experiments were carried out to promote an understanding of the combustion characteristics of combustibles in the building. Sofa and bed were used as combustibles in the experiment. Heat release rate of the sofa was about 1.9MW. Heat release rate of the bed was approximately 650kW.

A Study on Fire Characteristics of Carpet and Curtain Treated or Untreated with Flame Retardant (카페트와 커튼의 방염처리 및 사용여부에 따른 화재특성에 관한 연구)

  • Lee, Hae-Pyeong;Park, Young-Ju
    • Fire Science and Engineering
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    • v.21 no.1 s.65
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    • pp.74-81
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    • 2007
  • In this study, we have evaluated the hazardous factors of fires such as heat release rate, smoke density, ignition temperature, and flammability of carpet and curtain used in the public facilities. As a result of flame retardant treatment, the heat release rate of materials treated with flame retardant was lower than that of not treated. However, the smoke density of treated materials was higher than that of not treated. Also, we have investigated the fire characteristics of used and unused carpet. As a result, the heat release rate and the smoke density of used for 3 years carpet were higher than those of unused carpet. The distinct differences of flammability and ignition temperature between used and unused carpet were confirmed.