研究目的：本論文之研究主要旨在採用兩種非甾體抗炎藥--布洛芬（IBP）及氟比洛芬（FBP）來考察一項新型的納米粒子製備技術--瞬時納米沉澱技術（FNP）。IBP和FBP具有不同理化性質，但其親油性屬大部分藥物所具的典型親油性 （log P = 2-5）。研究證實IBP和FBP有治療阿爾茨海默氏病的潛在藥效，但在血液中廣泛與血漿蛋白結合，導致其腦血管通透性很低。因此，本研究的另一目的為考察FNP製備的納米處方是否能改善此類藥物的大腦遞送。 / 方法：應用FNP，用多入口渦旋混合器（MIVM）將藥物載入聚乙二醇-聚乳酸（PEG-PLA）的納米粒中。通過改變關鍵工藝流程變量考察了變量對納米粒物理性質及穩定性的影響。使用動態光散射儀測定了納米粒粒徑和粒徑分佈，使用zeta 電位分析測定了粒子表面電荷，使用原子力顯微鏡（AFM）確定了納米粒形態，使用x射線光電子能譜（XPS）分析了粒子表面化學成分，使用高效液相色譜測定了的處方載藥量和包封率。使用MDCK和Caco-2細胞株評估了優化後納米處方的細胞通透性，使用健康小鼠進行了優化后纳米處方的体内腦攝取實驗。 / 結果：IBP和FBP納米粒的粒徑均在30-100 nm的範圍內，粒徑分佈均低於或接近0.2。AFM結果顯示，納米粒具有近球狀形態。由多次線性回歸分析各工藝流程變量對IBP納米粒粒徑的影響所得相對重要性的結果為：PLA對PEG之分子量比 > 過飽和比 > 藥物對聚合物比 > 雷諾數。用相同統計方法分析FBP樣品所得結果顯示，PLA對PEG之分子量比亦為影響粒子粒徑的最重要變量。最穩定的IBP納米處方可以在懸浮液狀態下穩定超過1個月，而FBP納米處方為2天。IBP和FBP納米粒的載藥量和包封率均分別超過25%和70%。XPS，AFM和zeta電位測定結果共同表明納米粒中的PEG均偏重位於粒子表面，而相比之下，IBP納米粒中的PEG較FBP納米粒更加偏向於分佈於粒子表面。優化後的IBP納米粒由聚山梨醇酯80包裹後，與IBP溶液相比，顯著增加了IBP的健康小鼠腦攝取量。 / 結論：應用FNP及MIVM製備的聚合物IBP和FNP納米粒，粒徑小，粒徑分佈窄，重現性高，且有較高的載藥量和包封率。納米粒的粒徑主要取決於所採用的共聚物。IBP 納米粒子明顯優越的物理穩定性可歸功於粒子表面較高的PEG濃度。用聚山梨醇酯80包裹納米粒子對於提高IBP的大腦遞送有決定性作用。 / Objectives: The present thesis work was primarily aimed at assessing a relatively novel nanoparticle (NP) production technology termed flash nanoprecipitation (FNP) using two non-steroidal anti-inflammatory drugs, ibuprofen (IBP) and flurbiprofen (FBP), with different physiochemical properties and lipophilicity typical of most drugs (log P = 2-5). Both model drugs were proven to be of potential benefits to the treatment of Alzheimer’s disease, but exhibited poor brain delivery in vivo which could be ascribed to their extensive binding with plasma proteins in the blood. Therefore another aim of the present thesis was to determine whether FNP-produced NP formulations could enhance the delivery of these drugs into the brain. / Methods: Drugs were loaded into NPs of polyethylene glycol (PEG)-polylactic acid (PLA) copolymers of different molecular weights (MWs) by FNP using a four-stream multi-inlet vortex mixer (MIVM). The influence of several key processing variables on the physical properties and stability of the NPs was investigated. The NP preparations were characterized for particle size and size distribution by dynamic light scattering (DLS) sizing analysis; surface charges by zeta potential measurement; particle morphology by atomic force microscopy (AFM); surface composition by x-ray photoelectron spectroscopy (XPS); and drug loading (DL) and encapsulation efficiency (EE) by high performance liquid chromatography. Optimal IBP NP samples were assessed in vitro for cellular permeability using Caco-2 and MDCK cell lines and in vitro for brain uptake in normal mice. / Results: Both IBP and FBP NPs exhibited mean particle size in the range of 30-100nm and polydispersity below or around 0.2. The particles were nearly spherical in shape, as examined by AFM. Multiple linear regression analysis revealed that the relative impact of the processing variables on the particle size of IBP NPs followed the order: PLA-to-PEG MW ratio > supersaturation ratio > drug-to-copolymer ratio > Reynolds number. Similar statistical analysis for FBP NPs also indicated PLA-to-PEG MW ratio being the most significant determinant of particle size. The most stable IBP and FBP NPs in suspension form could last for over 1 month and 2 days respectively. NPs with DLs > 25% and EEs > 70% could be obtained by FNP. XPS in conjunction with AFM and zeta potential analysis revealed that PEG was located more on the surfaces of both IBP and FBP NPs than in the core, but the surface PEG density was higher for the IBP NPs. Coating of optimal IBP NPs with polysorbate 80 significantly improved the brain uptake of IBP in normal mice, compared to IBP solution. / Conclusion: Polymer-stabilized IBP and FBP NPs with particle size below 100 nm and narrow size distribution can be consistently generated by FNP using the MIVM. The copolymer used is the most important determinant of particle size. The superior physical stability of the IBP NPs can be ascribed to their relatively high surface PEG density. High DLs and EEs are achievable with the FNP process. Nanoparticle coating with polysorbate 80 is critical to enhancing the delivery of IBP to the brain in normal mice. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Xinran. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 205-245). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Table of Contents --- p.I / Acknowledgements --- p.VI / Abstract --- p.VIII / 摘要 --- p.X / List of Figures --- p.XII / List of Tables --- p.XVII / List of Abbreviations --- p.XIX / Chapter Chapter One --- Introduction / Chapter 1.1 --- Rationale of the study --- p.1 / Chapter 1.2 --- General review of nanoparticulate drug carrier systems --- p.4 / Chapter 1.2.1 --- Background of nanoscience --- p.4 / Chapter 1.2.2 --- Applications of nanoparticulate drug delivery systems --- p.4 / Chapter 1.2.2.1 --- Improved delivery of poorly water soluble drugs --- p.5 / Chapter 1.2.2.2 --- Targeted drug delivery --- p.6 / Chapter 1.2.2.3 --- Drug delivery across the blood brain barrier --- p.8 / Chapter 1.2.2.4 --- Other drug delivery applications --- p.10 / Chapter 1.2.3 --- Types of nanoparticulate drug delivery systems --- p.10 / Chapter 1.2.3.1 --- Nanocrystals --- p.10 / Chapter 1.2.3.2 --- Solid lipid nanoparticles --- p.11 / Chapter 1.2.3.2.1 --- Preparation methods --- p.12 / Chapter 1.2.3.2.2 --- Drug delivery --- p.12 / Chapter 1.2.3.3 --- Polymeric nanoparticles --- p.14 / Chapter 1.2.3.3.1 --- Preparation methods --- p.15 / Chapter 1.2.3.3.2 --- Drug delivery --- p.17 / Chapter 1.2.4 --- Characterization of nanoparticulate drug delivery systems --- p.20 / Chapter 1.2.4.1 --- Particle size and size distribution --- p.21 / Chapter 1.2.4.2 --- Morphology --- p.21 / Chapter 1.2.4.3 --- Zeta potential --- p.23 / Chapter 1.2.4.4 --- Surface chemical composition --- p.23 / Chapter 1.2.4.5 --- Crystallinity --- p.24 / Chapter 1.3 --- Flash Nanoprecipitation technique --- p.25 / Chapter 1.3.1 --- Mechanism and evolution --- p.25 / Chapter 1.3.2 --- Applications --- p.30 / Chapter 1.4 --- Ibuprofen and flurbiprofen --- p.32 / Chapter 1.4.1 --- General characteristics --- p.32 / Chapter 1.4.2 --- Physicochemical properties --- p.33 / Chapter 1.4.3 --- New therapeutic indications --- p.34 / Chapter 1.5 --- Scope of the thesis --- p.36 / Chapter Chapter Two --- Influence of Processing Variables on the Physical Properties and Stability of Ibuprofen and Flurbiprofen Nanosuspensions / Chapter 2.1 --- Introduction --- p.38 / Chapter 2.2 --- Materials and Methods --- p.39 / Chapter 2.2.1 --- Materials --- p.39 / Chapter 2.2.2 --- Solubility of ibuprofen and flurbiprofen in water and acetone mixtures --- p.39 / Chapter 2.2.3 --- Nanoparticle formulation preparation --- p.40 / Chapter 2.2.3.1 --- Determination of the minimum Reynolds number (Re) for homogenous mixing --- p.40 / Chapter 2.2.3.2 --- Effects of processing parameters on particle size and size distribution of ADCP-protected IBP and FBP nanoparticles. --- p.41 / Chapter 2.2.4 --- Particle size and size distribution measurement --- p.42 / Chapter 2.2.5 --- Statistics --- p.42 / Chapter 2.2.6 --- Assessment of nanosuspension stability --- p.42 / Chapter 2.3 --- Results and discussion --- p.43 / Chapter 2.3.1 --- Solubilities of ibuprofen and flurbiprofen in water and acetone mixtures --- p.43 / Chapter 2.3.2 --- Determination of the minimum Re for homogenous mixing --- p.44 / Chapter 2.3.3 --- Effects of processing parameters on particle size and size distribution of the ADCP-protected IBP and FBP nanoparticles. --- p.47 / Chapter 2.3.3.1 --- Effect of solvent type --- p.47 / Chapter 2.3.3.2 --- Effect of PLA-to-PEG MW ratio --- p.64 / Chapter 2.3.3.3 --- Effect of supersaturation --- p.64 / Chapter 2.3.3.4 --- Effect of Re --- p.70 / Chapter 2.3.3.5 --- Effect of drug-to-ADCP ratio --- p.71 / Chapter 2.3.4 --- Effects of processing parameters on the stability of ADCP-stabilized IBP and FBP nanoparticles --- p.72 / Chapter 2.3.4.1 --- Three-day stability --- p.72 / Chapter 2.3.4.2 --- Long-term stability --- p.83 / Chapter 2.4 --- Summary --- p.85 / Chapter Chapter Three --- Drying of Ibuprofen Nanoparticle Suspensions / Chapter 3.1 --- Introduction --- p.86 / Chapter 3.2 --- Materials and Methods --- p.88 / Chapter 3.2.1 --- Materials --- p.88 / Chapter 3.2.2 --- Preparation of IBP nanoparticle formulations with hydrophilic stabilizers or at refrigerated temperature --- p.89 / Chapter 3.2.3 --- Dialysis of nanoparticle formulations --- p.89 / Chapter 3.2.4 --- Freeze-thawing of selected nanoparticle preparations --- p.89 / Chapter 3.2.5 --- Freeze-drying of nanoparticle formulations --- p.90 / Chapter 3.2.6 --- Reconstitution --- p.90 / Chapter 3.2.7 --- Hydrogen bonding coacervate precipitation --- p.91 / Chapter 3.3 --- Results and discussion --- p.91 / Chapter 3.3.1 --- Preparation and dialysis of IBP nanoparticle formulations with hydrophilic stabilizers --- p.92 / Chapter 3.3.2 --- Freeze-drying using cryoprotectants and lyoprotectants --- p.94 / Chapter 3.3.3 --- Freeze-drying with different concentrations of glucose, sucrose and PVA --- p.101 / Chapter 3.3.4 --- Freeze-drying of nanoparticles prepared under other processing conditions --- p.105 / Chapter 3.3.5 --- Hydrogen bonding coacervate precipitation --- p.108 / Chapter 3.4 --- Summary --- p.110 / Chapter Chapter Four --- Physicochemical Characterization of Ibuprofen and Flurbiprofen Nanoparticles / Chapter 4.1 --- Introduction --- p.111 / Chapter 4.2 --- Materials and Methods --- p.112 / Chapter 4.2.1 --- Materials --- p.112 / Chapter 4.2.2 --- Encapsulation efficiency (EE) and drug loading (DL) of IBP nanoparticles --- p.112 / Chapter 4.2.3 --- HPLC analysis of IBP and FBP --- p.113 / Chapter 4.2.4 --- Nanoparticle morphology --- p.114 / Chapter 4.2.4.1 --- SEM --- p.114 / Chapter 4.2.4.2 --- AFM --- p.114 / Chapter 4.2.5 --- Zeta potential measurement --- p.115 / Chapter 4.2.6 --- Surface composition analysis --- p.115 / Chapter 4.3 --- Results and discussion --- p.116 / Chapter 4.3.1 --- Encapsulation efficiency (EE) and drug loading (DL) of IBP nanoparticles --- p.116 / Chapter 4.3.2 --- Nanoparticle morphology --- p.121 / Chapter 4.3.3 --- Surface charges of the nanoparticles --- p.126 / Chapter 4.3.4 --- Surface composition of nanoparticles --- p.128 / Chapter 4.4 --- Summary --- p.145 / Chapter Chapter Five --- Cellular Permeability and In Vivo Brain Uptake of Ibuprofen Nanoparticles / Chapter 5.1 --- Introduction --- p.146 / Chapter 5.2 --- Materials and methods --- p.148 / Chapter 5.2.1 --- Materials --- p.148 / Chapter 5.2.2 --- Methods --- p.148 / Chapter 5.2.2.1 --- Cellular permeability study --- p.148 / Chapter 5.2.2.1.1 --- Cell culture --- p.148 / Chapter 5.2.2.1.2 --- Cell viability study --- p.149 / Chapter 5.2.2.1.3 --- MDCK and Caco-2 cell monolayer permeability assay --- p.150 / Chapter 5.2.2.2 --- In vivo brain uptake study --- p.151 / Chapter 5.2.2.2.1 --- HPLC-UV analysis --- p.151 / Chapter 5.2.2.2.2 --- Preparation of calibration samples --- p.151 / Chapter 5.2.2.2.3 --- Sample preparation --- p.152 / Chapter 5.2.2.2.4 --- Validation of assay methods --- p.153 / Chapter 5.2.2.2.5 --- Animal experiments --- p.154 / Chapter 5.2.2.2.6 --- Data Analysis --- p.155 / Chapter 5.3 --- Results and discussion --- p.155 / Chapter 5.3.1 --- Cellular permeability study --- p.155 / Chapter 5.3.1.1 --- Cell viability study --- p.155 / Chapter 5.3.1.2 --- MDCK and Caco-2 cell monolayer permeability assay --- p.157 / Chapter 5.3.2 --- In vivo brain uptake study --- p.158 / Chapter 5.3.2.1 --- Method validation --- p.158 / Chapter 5.3.2.2 --- Brain uptake of IBP nanoparticles --- p.159 / Chapter 5.4 --- Summary --- p.166 / Chapter Chapter Six --- Conclusions and Future Studies / Chapter 6.1. --- Conclusions --- p.167 / Chapter 6.2. --- Future studies --- p.172 / Appendices --- p.174 / References --- p.205
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328032 |
| Date | January 2013 |
| Contributors | Zhang, Xinran., Chinese University of Hong Kong Graduate School. Division of Pharmacy. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (xix, 245 leaves) : ill. (some col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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