36,981 research outputs found
Phase transitions in two-dimensional colloidal particle system observed in Langmuir trough
No full textLiquid-Liquid Equilibria for the Ternary System Water + Decane + Diethylene Glycol Monobutyl Ether at 20 ?C, 30 ?C, and 40 ?C
No full textCombining svms with various feature selection strategies
No full textcombining svms with various feature. selection strategies. yi-wei chen & chih-jen lin. department of computer science. national taiwan university. taipei 106. taiwan. summary. this article investigates the performance of combinin
Liquid–liquid equilibria for the ternary system water + tetradecane + 2-butyloxyethanol
No full textLiquid–liquid equilibria of the ternary system water + tetradecane + 2-butyloxyethanol in the temperature range from 298.15 to 338.15K
were investigated at atmospheric pressure. The experimental data correlated well with the UNIQUAC model. For the system with a
three-liquid-phase-coexisting region, all the six UNIQUAC interaction parameters can be determined numerically by minimizing the deviation
of the compositions of three coexisting liquid phases only
MagNetUS 2021 - Day 3 - L. Chen - Multi-scale solitary structures in space and laboratory
No full textMagNetUS 2021 - Day 3
Speaker: Li-Jen Chen
Title: Multi-scale solitary structures in space and laborator
Chen Jen Hao (1908-1976): A biography
No full text"Prominent Figures of the World Fujian Communities – The Singapore Chapter 1819-2012", published by the Singapore Hokkien Huay Kuan, contains the deeds of 150 Singaporean Hokkien scholars and their contributions to the country. The chapter on Chen Jen Hao introduces the life of the pioneer. Chen served as the principal of Kallang West Government Chinese Middle School (now Dunman High School) in 1956 and retired in 1969. During his time as the principal, Chen inculcated a strong interest in calligraphy amongst the students. This chapter integrates Chen's legendary life as an educator, calligrapher and painter, and reveals his lasting impact on the Singapore society
Micronization and Encapsulation of Pharmaceutical Compounds Using Supercritical Anti-Solvent Precipitation Process
No full text本研究以超臨界反溶劑法(SAS)法，進行高分子及藥物微粒化，超臨界CO2扮演反溶劑的角色，使得溶液體積膨脹，溶液迅速達過飽和而析出溶質。本研究利用超臨界反溶劑法，成功地將PMMA, CA, HPC等高分子微粒化。Hydrochlorothiazide (HCT, 利尿劑), Tolazamide, Succinic acid, Naringin等藥物經過SAS操作，亦得到良好的微粒化效果。
在本研究選定利尿劑HCT進行操作參數的探討，在不同的壓力、溫度、溶液濃度、溶液流速下進行實驗，探討各參數對粒徑及晶貌的影響。研究結果顯示，在壓力為120bar，溫度為45℃，溶液濃度為10%飽和濃度及溶液流率為0.25mL/min時，可得最小的HCT粒徑為0.67µm。
本研究又以利尿劑HCT為核心藥物，生物可分解性高分子PLA為殼層物質進行包覆，並探討原始藥物、微粒化藥物及包覆後藥物的溶離速率情形。經由本研究SAS操作得到的微粒化HCT藥物之溶離速率，較原始藥物提升了3倍，而包覆後的微囊，具有延長釋放的效果，且其釋放動態模式，符合Higuchi釋放動力模式。The purpose of this study was to apply the technique, supercritical anti-solvent (SAS) to the preparation of micronized polymers and drugs. In the SAS process, supercritical CO2 acts as an anti-solvent for the solution. The supercritical CO2 causes supersaturation of the solution, leading to nucleation and precipitation of the solute rapidly. The polymers such as PMMA, CA, HPC were successfully micronized using the SAS process. At the same time, the size of drugs such as Hydrochlorothiazide (HCT), Tolazamide, Succinic acid and Naringin were also greatly reduced after the SAS process.
In this research, the effect of the process parameters was discussed using HCT as model drug. The operating parameters that have an effect on the size of the drug, such as pressure, temperature, concentration of solution and flow rate of solution, were systematically studied to find the optimum operating parameters. We got the smallest average particle size, 0.67µm of HCT at the condition that P=120bar, T=45℃,solution concentration=10% sat., solution flow rate=0.25mL/min.
Encapsulation of fine particles with polymer using the supercritical antisolvent coating process was also investigated in this research. The diuretic drug, HCT particles were used as host particles and PLA, a biodegradable polymer used for controlled release of drugs, was chosen as the coating material. This study also discussed the dissolution rates of original, micronized and encapsulated drugs. The dissolution rate of micronized HCT which were obtained after continuous SAS was 3 times greater than that of the original drug. The encapsulated drug allows a slow and prolonged drug release and the release profile of the encapsules matches the Higuchi matrix release kinetic model.中文摘要 I
英文摘要 II
目錄 III
表目錄 V
圖目錄 VI
第一章 緒論 1
1-1超臨界流體介紹 1
1-2超臨界流體技術應用於藥物微粒化 1
1-3控制釋放 8
1-4超臨界流體技術應用於藥物包覆 10
1-5藥物微粒溶離動力學與藥物釋放動力模式 12
1-6目標藥物介紹 18
第二章 實驗方法 22
2-1 實驗裝置 22
2-2 實驗操作步驟 23
2-2-1 目標藥物可溶性之測試 23
2-2-2 連續式超臨界反溶劑沉積操作步驟 23
2-3 分析方法 25
2-3-1藥物顆粒型態與粒徑大小分析 25
2-3-2藥物結晶特性分析 26
2-3-3藥物熱效應分析 26
2-3-4藥物定性分析 27
2-3-5藥物包覆組成與有效負載率分析 27
2-4溶離速率試驗 28
2-5實驗設計 29
第三章 結果與討論 31
3-1超臨界反溶劑微粒化結果 31
3-1-1高分子微粒化之結果 31
3-1-2藥物微粒化之結果 34
3-2連續式超臨界反溶劑微粒化操作參數探討 36
3-3超臨界反溶劑包覆結果 41
3-3-1藥物包覆定性分析 41
3-3-2藥物包覆定量分析 43
3-4藥物溶離速率及釋出結果 44
第四章 結論 47
參考文獻 10
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