This study provides, for the first time, an ex vivo comparative evaluation of formulations of budesonide with crystallised β-form mannitol, commercial DPI grade mannitol and lactose. The lactose-budesonide was the marketed Easyhaler® 200 g formulation. Ex vivo assessment of deposition using the Easyhaler® multi-dose high resistance inhaler with reservoir was compared with the RS01® single dose capsule low resistance inhaler at two different inhalation rates. Aerodynamic characteristics, flow and surface energies were investigated together with in vitro and ex vivo assessment of drug deposition. Dose emission was greater for all formulations with higher inhalation flow, indicating greater detachment of drug from carrier, and greater with the Easyhaler®, highlighting the importance of correct device for formulation. Emission was lowest at both inhalation rates for crystallised mannitol due to poor flowability associated with elongated particle shape which resulted in interception deposition. Surface energies were also implicated; closely matched polar surface energy of carrier and drug may be an important inhibiting factor. The promising aerodynamic characteristics of crystallised mannitol with the RS01® inhaler and lactose-budesonide from in vitro assessment were not supported by ex vivo results, highlighting the need for careful selection of device.

This thesis is based around examination of three mainstream inhaled drugs Formoterol, Budesonide and Beclomethasone for treatment of asthma and COPD. The areas investigated are these which have been raised in reports and studies, where there are concern, for drug use and assessment of their use. In reporting this work the literature study sets out a brief summary of the background and anatomy and physiology of the respiratory system and then discuses the mechanism of drug deposition in the lung, as well as the methods of studying deposition and pulmonary delivery devices. This section includes the basis of asthma and COPD and its treatment. In addition, a short section is presented on the role of the pharmacist in improving asthma and COPD patient's care. Therefore the thesis is divided into 3 parts based around formoterol, budesonide and beclomethasone. In the first case the research determines the in-vitro performance of formoterol and budesonide in combination therapy. In the initial stage a new rapid, robust and sensitive HPLC method was developed and validated for the simultaneous assay of formoterol and the two epimers of budesonide which are pharmacologically active. In the second section, the purpose was to evaluate the aerodynamic characteristics for a combination of formoterol and the two epimers of budesonide at inhalation flow rates of 28.3 and 60 L/min. The aerodynamic characteristics of the emitted dose were measured by an Anderson cascade impactor (ACI) and the next generation cascade impactor (NGI). In all aerodynamic characterisations, the differences between flow rates 28.3 and 60 were statistically significant in formoterol, budesonide R and budesonide S, while the differences between ACI and NGI at 60 were not statistically significant. Spacers are commonly used especially for paediatric and elderly patients. However, there is considerable discussion about their use and operation. In addition, the introduction of the HFAs propellants has led to many changes in the drug formulation characteristics. The purpose of the last section is to examine t h e performance of different types of spacers with different beclomethasone pMDIs. Also, it was to examine the hypothesis of whether the result of a specific spacer with a given drug/ brand name can be extrapolated to other pMDIs or brand names for the same drug. The results show that there are different effects on aerodynamic characterisation and there are significant differences in the amount of drug available for inhalation when different spacers are used as inhalation aids. Thus, the study shows that the result from experiments with a combination of a spacer and a device cannot be extrapolated to other combination.

This thesis is based around examination of three mainstream inhaled drugs Formoterol, Budesonide and Beclomethasone for treatment of asthma and COPD. The areas investigated are these which have been raised in reports and studies, where there are concern, for drug use and assessment of their use. In reporting this work the literature study sets out a brief summary of the background and anatomy and physiology of the respiratory system and then discuses the mechanism of drug deposition in the lung, as well as the methods of studying deposition and pulmonary delivery devices. This section includes the basis of asthma and COPD and its treatment. In addition, a short section is presented on the role of the pharmacist in improving asthma and COPD patient¿s care. Therefore the thesis is divided into 3 parts based around formoterol, budesonide and beclomethasone. In the first case the research determines the in-vitro performance of formoterol and budesonide in combination therapy. In the initial stage a new rapid, robust and sensitive HPLC method was developed and validated for the simultaneous assay of formoterol and the two epimers of budesonide which are pharmacologically active. In the second section, the purpose was to evaluate the aerodynamic characteristics for a combination of formoterol and the two epimers of budesonide at inhalation flow rates of 28.3 and 60 L/min. The aerodynamic characteristics of the emitted dose were measured by an Anderson cascade impactor (ACI) and the next generation cascade impactor (NGI). In all aerodynamic characterisations, the differences between flow rates 28.3 and 60 were statistically significant in formoterol, budesonide R and budesonide S, while the differences between ACI and NGI at 60 were not statistically significant. Spacers are commonly used especially for paediatric and elderly patients. However, there is considerable discussion about their use and operation. In addition, the introduction of the HFAs propellants has led to many changes in the drug formulation characteristics. The purpose of the last section is to examine t h e performance of different types of spacers with different beclomethasone pMDIs. Also, it was to examine the hypothesis of whether the result of a specific spacer with a given drug/ brand name can be extrapolated to other pMDIs or brand names for the same drug. The results show that there are different effects on aerodynamic characterisation and there are significant differences in the amount of drug available for inhalation when different spacers are used as inhalation aids. Thus, the study shows that the result from experiments with a combination of a spacer and a device cannot be extrapolated to other combination.

Aerosol electrostatics is an important property of pharmaceutical aerosols. The electrostatic properties of pMDI aerosols have been shown to be a function of both formulation and packaging components. The modified ELPI enables measurement of aerosol charge as a function of particle size, and the simultaneous determination of the mass distribution using chemical analysis. However, in order to fully assess the cause and effects of aerosol electrostatics in terms of its biological and regulatory implications, it is necessary to understand the basic charging mechanisms inside the pMDI formulation. Electrical resistivity and zeta potential measurements confirmed the presence of charged species within HFA based solutions and suspensions although the nature of these species remains unknown. These measurements were influenced by the cosolvent concentration and to a lesser extent by the presence of soluble drug and surfactant. The mean electrical resistivity of a 7% ethanol / 93% HFA 134a blend (0.83 ± 0.02 MΩ.cm) was significantly lower than that reported for HFA 134a (180 MΩ.cm). Albuterol sulfate demonstrated a positive zeta potential (75.9 ± 26.2 mV) in HFA 134a. Pilot molecular modeling studies, in conjunction with the analysis of particle interactions using HINT, provided an improved understanding of the possible interactions within albuterol sulfate HFA suspension pMDIs. The predominantly negative (-7597 ± 2063) HINT score signified unfavorable interactions between albuterol sulfate and HFA 134a molecules. Systematic investigations of the electrical properties of HFA solution and suspension pMDIs using the modified ELPI demonstrated that the electrical properties were a function of the formulation type (solution/suspension), formulation components and particle size. Experimental BDP solution pMDIs produced predominantly electropositive aerosols (net charge: 160 ± 30 pC) while albuterol sulfate pMDIs produced bipolar charged aerosol clouds (net charge: -162 ± 277 pC). Finally, the modified ELPI was recalibrated using commercially available polydisperse pMDIs as calibration aerosols with a reference Andersen cascade impactor. The mean cut-off diameters for stages 4-12 obtained following recalibration of the modified ELPI were 0.44, 0.56, 0.70, 1.01, 1.40, 2.12, 3.03, 4.75, 6.37 μm, respectively in comparison to those reported by the manufacturer (0.16, 0.27, 0.39, 0.62, 0.96, 1.62, 2.42, 4.05, 6.67 μm, respectively).

Made available in DSpace on 2014-08-20T13:57:59Z (GMT). No. of bitstreams: 1 Dissertacao_Paula_Oliveira.pdf: 1081819 bytes, checksum: 9e319c71a8b01c131e6f3917156db97d (MD5) Previous issue date: 2012-12-14 / Objective: to evaluate the characteristics of the users of metered-dose inhalers and its prevalence, among those who reported a diagnosis of asthma, bronchitis and/or emphysema. Methods: a population-based study in Pelotas, RS, Brazil, including 3,670 subjects aged 10 years or older. Results: About 10% of the sample referred at least one respiratory disease. Among these, 59% referred symptoms in the last year and of those, only half have used inhalers, showing difference between the quintiles of socioeconomic status (39% poorest quintile vs. 61% richest quintile p=0,01). There was no difference in the use of inhalers by age and sex. Regarding the pharmacological group, the emphysematous used a combination of bronchodilator (BD) plus corticosteroids in greater proportion than just BD. Only among those who reported a medical diagnosis of asthma and with actual symptoms, the proportion of use of inhalers was higher than 50%. Conclusion: metered-dose inhalers are underused among those who relate these diagnoses and the type of medicine used by the ones who referred emphysema is not in accordance with the recommendations in the consensus about these diseases. / Objetivo: avaliar as características dos usuários de inaladores dosimetrados e sua prevalência de uso, entre aqueles que referem diagnóstico de asma, bronquite e/ou enfisema. Métodos: estudo de base populacional realizado em Pelotas, RS, incluindo 3670 indivíduos, com 10 anos de idade ou mais. Resultados: Cerca de 10% da amostra referiu pelo menos uma das doenças respiratórias investigadas. Entre eles, 59% apresentaram sintomas no último ano e, destes, apenas metade usou inaladores, havendo diferença entre os quintis de nível socioeconômico (39% quintil mais pobre vs. 61% no quintil mais rico p=0,01). Não houve diferença no uso de inaladores por sexo e idade. Quanto ao grupo farmacológico, os enfisematosos utilizaram a combinação broncodilatador (BD) + corticoide em maior proporção do que apenas BD. Somente dentre os que referiram diagnóstico médico de asma e sintomas atuais, a proporção de uso de inalador foi maior que 50%. Conclusão: os inaladores dosimetrados são subutilizados entre os que referem estes diagnósticos e que o tipo de medicamento usado por aqueles que referiram enfisema não está de acordo com o preconizado nos consensos sobre estas doenças.

A number of therapeutic proteins are used for long in clinical practice. These include for example insulin, calcitonine, growth hormone, and parathyroid hormone for the treatment of various systemic disorders, as well as protein antigens in vaccine formulations. Due to the recent developments in biochemical engineering and in the comprehension of the physiopathology of many diseases, peptides and proteins are expected to become a drug class of increasing importance. Recently, novel biological drugs have for example been developed such as monoclonal antibodies, antibody fragments, soluble receptors, and receptor agonists or antagonists. These are mainly used for the treatment of auto-immune and inflammatory diseases (asthma, rheumatoid arthritis) and for the treatment of cancers. However, a major drawback of these biomolecules is the need to use parenteral administration. This is mainly due to the harsh pH conditions that proteins undergo by oral administration, leading to various physico-chemical degradations and loss of biological activity. <p><p>Pulmonary delivery of these proteins could constitute an alternative to parenteral delivery. Due to the very high surface area of the lungs, the low thickness of the alveolar epithelium and the high level of lung vascularisation, pulmonary administration can indeed provide fast systemic absorption of drugs, while avoiding hepatic first pass metabolism. On the other hand, drugs for local treatment can also be administered directly into the lung, which allows delivering high doses while limiting systemic side effects. Nevertheless, administration of drugs to the lungs requires some challenges to be taken up. It is indeed necessary to provide the drug as very small solid or liquid microparticles (1-5 µm) in order to reach the lungs. For solid microparticles, it is also needed to overcome the very high inter-particle interactions by using appropriate formulation strategies and by including deaggregation mechanisms in the inhalation device. Other issues are more specifically related to the pulmonary administration of proteins. These can indeed undergo physico-chemical degradations during processing, administration, and/or storage. Moreover, if systemic action is required, proteins will often need addition of an absorption enhancer to cross the alveolar epithelium because of their large molecular weight and hydrophilicity. <p><p>In this work, we developed formulations for pulmonary delivery of proteins using two model proteins. Insulin (5.8 kDa) was chosen as a model of small protein. It is also an application of systemic pulmonary delivery. On the other hand, an anti-IL13 monoclonal antibody fragment (54 kDa) was used as a model of larger protein. This molecule is currently in development for the treatment of asthma and provided an application for local pulmonary delivery. The formulation strategy was to produce dry powders using a combination of micronisation techniques (high speed and high pressure homogenisations), drying techniques (spray-drying, freeze-drying), and addition of lipid excipients. These lipid excipients were added as a coating around the protein particles and were expected to prevent protein degradations during processing and/or storage, essentially by avoiding contact with water. It could also improve the aerodynamic properties of the powders by modification of the surface properties of the particles and/or limitation of the capillary forces.<p><p>First, we evaluated insulin lipid-coated formulations and formulations without excipients, produced using high pressure homogenisation and spray-drying. In the case of lipid-coated formulations, a physiological lipid composition based on a mixture of cholesterol and phospholipids was used. We were able to obtain good aerodynamic features for the different formulations tested, with fine particle fractions between 46% and 63% versus 11% for raw insulin powder. These are high FPF values in comparison with those obtained for other protein formulations for inhalation currently under development, which often have an in vitro deposition of around 30%. Insulin presented a good stability in the dry state, even when no lipid coating was added.<p>The presence of a lipid coating of up to 30% (w/w) did not significantly improve the aerodynamic behaviour of the powders, but the coated formulations exhibited decreased residual moisture content after 3-month storage, which should be of interest for the long-term stability of the formulations. <p><p>In a second step, two of the developed insulin formulations were evaluated in a clinical study to determine whether the formulations give high deep lung deposition in vivo, and how insulin is absorbed into the systemic blood stream. This pharmaco-scintigraphic trial was performed on twelve type 1 diabetic patients using an uncoated formulation and a formulation coated with 20% (w/w) of lipids. The two formulations showed interesting features, with pharmacokinetic profiles that mimic the natural insulin secretion pattern. Bioavailability was within the ranges of two of the three dry powder insulins that have reached phase III clinical development. However, the formulation with a lipid coating exhibited a lower lung deposition in comparison with the uncoated formulation, which was not expected from the previous in vitro results. Additional in vitro experiments indicated that this lower performance was related to a decrease in the disaggregation efficiency of the powder at a sub-optimal inhalation flow-rate. An extensive training of the patients to the inhalation procedure could therefore improve the lung deposition of the coated formulation.<p><p>Finally, we developed and evaluated dry powder formulations of the anti-IL13 antibody fragment. These were produced using, successively, freeze-drying, high pressure homogenisation (HPH), and spray-drying. The influence of different types and concentrations of stabilising excipients was evaluated for each production step. Due to its more elaborated structure, the antibody fragment was found to be more sensitive than insulin to physico-chemical degradation, particularly during the HPH process, which led to different types of degradation products. These could partly be avoided by adding 50% sucrose during freeze-drying and 10% Na glycocholate or palmitic acid in the liquid phase during HPH (dispersing agents). However, the presence of a small fraction of insoluble aggregates could not be fully avoided. Further spray-drying of the suspensions in the presence of 10% Na glycocholate or palmitic acid led to the formation of a hydrophilic or hydrophobic coating around the particles, respectively. Na glycocholate was found to be particularly effective in protecting the antibody during spray-drying, which was found to be at least partly related to its ability to inhibit sucrose recrystallisation. However, the best formulation still presented a small fraction of insoluble aggregates (6%). The aerodynamic evaluation of the formulations showed FPFs that were compatible with lung deposition, with the formulation containing Na glycocholate presenting the highest FPF (42%). The formulation coated with palmitic acid presented a slightly lower FPF (35%). The aerodynamic properties of this formulation remained unchanged at a sub-optimal inspiratory flow rate, to the contrary of what was observed for the insulin formulation coated with 20% (w/w) cholesterol and phospholipids. Palmitic acid could therefore be of interest as a hydrophobic coating material, and provide long-term stability of protein drugs. <p>The work performed with the insulin and anti-IL13 molecules provided the proof-of-concept that it was possible to obtain dry powder protein formulations with appropriate aerodynamic properties and good overall physico-chemical stability, using simple production techniques and few selected excipients. The formulation strategy presented in this work could therefore be of interest for the future development of inhaled proteins for local or systemic applications. <p> / Doctorat en sciences pharmaceutiques / info:eu-repo/semantics/nonPublished

Dry powder inhalers (DPI), used as a means for pulmonary drug delivery, typically contain a combination of active pharmaceutical ingredients (API) and significantly larger carrier particles. The microsized drug particles-which have a strong propensity to aggregate and poor aerosolization performance-are mixed with significantly large carrier particles that cannot penetrate the mouth-throat region to deagglomerate and entrain the smaller API particles in the inhaled airflow. Therefore, a DPI's performance depends on the carrier-API combination particles' entrainment and the time and thoroughness of the individual API particles' deagglomeration from the carrier particles. Since DPI particle transport is significantly affected by particle-particle interactions, particle sizes and shapes present significant challenges to computational fluid dynamics (CFD) modelers to model regional lung deposition from a DPI. We employed the Particle-In-Cell method for studying the transport/deposition and the agglomeration and deagglomeration for DPI carrier and API particles in the present work. The proposed development will leverage CFD-PIC and sensitivity analysis capabilities from the Department of Energy laboratories: Multiphase Flow Interface Flow Exchange and Dakota UQ software. A data-driven framework is used to obtain the reliable low order statics of the particle's residence time in the inhaler. The framework is further used to study the effect of drug particle density, carrier particle density and size, fluidizing agent density and velocity, and some numerical parameters on the particles' residence time in the inhaler.

There has been very little research into the bioanalytical application of Microemulsion High Performance Liquid Chromatography (MELC), a recently established technique for separating an active pharmaceutical ingredient from its related substances and for determining the quantity of active drug in a dose. Also, the technique is not good at separating hydrophilic drugs of very similar chemical structures. Different phase diagrams of oil (octane or ethyl acetate), co-surfactant (butanol), surfactant (sodium dodecyl sulphate (SDS) or Brij-35) and buffer (Phosphate pH 3) were developed and several nanoemulsion mobile phases identified. Nanoemulsion mobile phase that is, prepared with SDS, octane, butanol and a phosphate buffer, failed to separate hydrophilic compounds with a very close chemical structure, such as terbutaline and salbutamol. A nanoemulsion mobile phase containing a non-ionic surfactant (Brij-35) with ethyl acetate, butanol and a phosphate buffer, was, however, successful in achieving a base line separation, and the method was validated for simultaneous determination of terbutaline and salbutamol in aqueous and urine samples. An oil-in-water (O/W) NELC method was developed and validated for the determination of formoterol in an Oxis® Turbuhaler® using pre-column fluorescence derivatisation. Although the same mobile phase was extended for separation of formoterol in urine, the formoterol peak's overlap with endogenous peaks meant that fluorescence detection could not determine formoterol in urine samples. Solid phase extraction, concentrating the final analyte 40 times, enabled determination of a low concentration of formoterol in urine samples by UV detection. The method was validated and an acceptable assay precision %CV <4.89 inter-day and %CV <2.33 intra-day was achieved. Then after the application of O/W nanoemulsion mobile phase for HPLC was extended for the separation of lipophilic drugs. The nanoemulsion liquid chromatography (NELC) method was optimised for the determination of salmeterol and fluticasone propionate in good validation data was achieved. This thesis shows that, in general, the performance of O/W NELC is superior to that of conventional High Performance Liquid Chromatography (HPLC) for the analysis of both hydrophilic and lipophilic drugs in inhaled dosage formulations and urine samples. It has been shown that NELC uses cheaper solvents and that analysis time is faster for aqueous and urine samples. This considerable saving in both cost and time will potentially improve efficiency within quality control.

Chan, Ka Man Carmen. / "October 2009." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 160-165). / Abstracts in English and Chinese. / Table of Contents --- p.I / Acknowledgements --- p.IV / Abstract --- p.V / Abstract (Chinese version) --- p.VIII / List of Figures --- p.X / List of Tables --- p.XVIII / Chapter Chapter One. --- Introduction / Chapter 1.1 --- Pulmonary drug delivery --- p.1 / Chapter 1.2 --- Inhalation drug delivery systems --- p.4 / Chapter 1.3 --- Dry powder inhalation aerosols --- p.5 / Chapter 1.3.1 --- Principle of operation of DPIs --- p.5 / Chapter 1.3.2 --- Aerodynamic diameter --- p.6 / Chapter 1.3.2.1 --- Fine particle fraction --- p.8 / Chapter 1.3.3 --- Dispersibility --- p.8 / Chapter 1.3.4 --- Factors that affect dispersibility --- p.9 / Chapter 1.3.4.1 --- Particle Size --- p.9 / Chapter 1.3.4.2 --- Particle Density and Morphology --- p.10 / Chapter 1.3.4.3 --- Interparticulate interactions一Cohesion and adhesion --- p.11 / Chapter 1.3.4.3.1 --- Surface energetics --- p.11 / Chapter 1.3.4.3.2 --- Effect of hygroscopicity and electrostatic charges --- p.12 / Chapter 1.4 --- Particle formation techniques for DPI formulation --- p.14 / Chapter 1.4.1 --- Spray-drying --- p.14 / Chapter 1.4.2 --- Surface modification --- p.16 / Chapter 1.5 --- Physical characterization --- p.17 / Chapter 1.5.1 --- Laser diffraction --- p.17 / Chapter 1.5.2 --- X-ray powder diffraction --- p.18 / Chapter 1.5.3 --- Thermal analysis --- p.19 / Chapter 1.5.4 --- Particle morphology and surface area --- p.20 / Chapter 1.5.5 --- In vitro aerosol performance --- p.21 / Chapter 1.6 --- Surface characterization --- p.21 / Chapter 1.6.1 --- X-ray photoelectric spectroscopy (XPS) --- p.21 / Chapter 1.6.2 --- Inverse gas chromatography --- p.22 / Chapter 1.7 --- Atomic force microscopy in pharmaceutical science --- p.23 / Chapter 1.7.1 --- Principle of operation --- p.24 / Chapter 1.7.1.1 --- Tapping mode --- p.27 / Chapter 1.7.1.2 --- Contact mode --- p.27 / Chapter 1.8 --- Scope of thesis --- p.29 / Chapter Chapter Two. --- Materials and Methods / Chapter 2.1 --- Materials --- p.32 / Chapter 2.2 --- Methods --- p.32 / Chapter 2.2.1 --- Optimization of spray-drying parameters --- p.32 / Chapter 2.2.2 --- Preparation of spray-dried salbutamol sulphate powders containing different concentrations of amino acid additive --- p.33 / Chapter 2.2.3 --- Physical characterization of spray-dried powders --- p.34 / Chapter 2.2.3.1 --- Particle size and size distribution --- p.34 / Chapter 2.2.3.2 --- Specific surface area --- p.35 / Chapter 2.2.3.3 --- X-ray powder diffraction --- p.35 / Chapter 2.2.3.4. --- Scanning electron microscopy --- p.36 / Chapter 2.2.3.5. --- Thermal analysis --- p.36 / Chapter 2.2.3.5.1 --- Thermogravimetric analysis (TGA) --- p.36 / Chapter 2.2.3.5.2 --- Differential scanning calorimetry (DSC) --- p.36 / Chapter 2.2.3.6 --- Water vapour sorption isotherm --- p.37 / Chapter 2.2.3.7 --- Density measurements --- p.37 / Chapter 2.2.3.8 --- In vitro particle deposition (MSLI) --- p.38 / Chapter 2.2.4 --- Surface characterization of the spray-dried powders --- p.39 / Chapter 2.2.4.1 --- X-ray photoelectric spectroscopy (XPS) --- p.39 / Chapter 2.2.4.2 --- Surface energy measurement by inverse gas chromatography (IGC) --- p.40 / Chapter 2.2.4.2.1 --- Calculation of standard free energy of adsorption --- p.41 / Chapter 2.2.4.2.2 --- Dispersive component of surface free energy and related thermodynamic parameters --- p.42 / Chapter 2.2.4.2.3 --- Specific interactions and associated acid-base properties --- p.43 / Chapter 2.2.5. --- Atomic Force Microscopy (AFM) --- p.43 / Chapter 2.2.5.1. --- Imaging --- p.43 / Chapter 2.2.5.2. --- Force measurements --- p.44 / Chapter 2.2.5.2.1 --- Adhesion force measurements --- p.44 / Chapter 2.2.5.2.2 --- Force curve data conversions --- p.44 / Chapter Chapter Three. --- "Optimal Spray-drying Conditions, Physical Characterization and Aerosol Performance of Additive-modified Spray-dried Salbutamol Sulphate particles" / Chapter 3.1 --- Optimization of spray-drying conditions --- p.46 / Chapter 3.2 --- Effect of phenylalanine on the spray-dried SS particles --- p.52 / Chapter 3.2.1. --- Phenylalanine as the additive --- p.52 / Chapter 3.2.1.1 --- In vitro aerosol performance --- p.53 / Chapter 3.2.1.2 --- Particle morphology --- p.55 / Chapter 3.2.1.3 --- Crystallinity --- p.62 / Chapter 3.2.1.4 --- Particle size distribution and specific surface area --- p.63 / Chapter 3.2.1.5 --- Density --- p.65 / Chapter 3.2.1.6 --- Thermal analysis --- p.66 / Chapter 3.2.1.7 --- Water vapour isotherm --- p.70 / Chapter 3.3 --- Effect of leucine on the spray-dried SS particles --- p.77 / Chapter 3.3.1. --- L-Leucine as the additive --- p.77 / Chapter 3.3.1.1 --- In vitro aerosol performance --- p.78 / Chapter 3.3.1.2 --- Particle morphology --- p.80 / Chapter 3.3.1.3 --- Crystallinity --- p.86 / Chapter 3.3.1.4 --- Particle size distribution and specific surface area --- p.87 / Chapter 3.3.1.5 --- Density --- p.90 / Chapter 3.3.1.6 --- Thermal analysis --- p.92 / Chapter 3.3.1.7 --- Water vapour isotherm --- p.95 / Chapter Chapter Four. --- Surface Characterization of Additive-modified Spray-dried Salbutamol Sulphate Particles / Chapter 4.1 --- X-ray photoelectric spectroscopy --- p.103 / Chapter 4.1.1 --- Phenylalanine --- p.103 / Chapter 4.1.2 --- Leucine --- p.104 / Chapter 4.2 --- Inverse gas chromatography --- p.105 / Chapter 4.2.1 --- Phenylalanine --- p.105 / Chapter 4.2.2 --- Leucine --- p.107 / Chapter 4.3 --- Atomic force microscopy --- p.109 / Chapter 4.3.1 --- Surface topography --- p.109 / Chapter 4.3.2 --- Adhesive force measurements --- p.118 / Chapter Chapter Five. --- Conclusions and Suggestions for Future Works / Chapter 5.1 --- Conclusions --- p.139 / Chapter 5.1.1 --- Physical properties --- p.139 / Chapter 5.1.2 --- Surface characteristics and aerosol performance --- p.140 / Chapter 5.2 --- Future studies --- p.142 / Appendix --- p.143 / References --- p.160

Chan, Pui. / "November, 2009." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 108-114). / Abstracts in English and Chinese. / Table of Contents --- p.i / Acknowledgement --- p.vi / Abstract --- p.vii / Abstract (Chinese) --- p.ix / Chapter Chapter One --- Introduction / Chapter 1.1. --- Pulmonary Route for Drug Delivery --- p.2 / Chapter 1.2. --- Factors Affecting the Performance of Inhaled Formulations --- p.3 / Chapter 1.2.1. --- Particle Aerodynamic Diameter --- p.4 / Chapter 1.2.2. --- Dispersibility of Particles --- p.5 / Chapter 1.2.3. --- Clearance Mechanism in Lung and Dissolution of Particles --- p.6 / Chapter 1.3. --- Production of Dry Powder Inhalation by Spray Drying --- p.7 / Chapter 1.4. --- Approaches to Enhance Aerosol Performance of Spray Dried Particles --- p.8 / Chapter 1.4.1 --- Porous/Hollow Particles --- p.9 / Chapter 1.4.2 --- Non-Porous Corrugated Particles --- p.10 / Chapter 1.4.3 --- Blends and Ternary Systems --- p.10 / Chapter 1.4.4 --- Surface Energy and Crystallinity Modification --- p.11 / Chapter 1.4.5 --- Other Approaches to Enhancing Aerosol Performance --- p.12 / Chapter 1.5 --- Objectives and Rationale of the Present Study --- p.13 / Chapter 1.6 --- Scope of Present Study and Particle Characterization Techniques Employed --- p.14 / Chapter 1.6.1 --- Microscopy and Particle Density Measurements --- p.14 / Chapter 1.6.2 --- Particle Size Analysis and Particle Dispersibility --- p.15 / Chapter 1.6.3 --- Thermal Analysis and Particle Crystallinity --- p.15 / Chapter 1.6.4 --- Particle Surface Characterization --- p.16 / Chapter 1.6.5 --- Inverse Gas Chromatography --- p.18 / Chapter 1.6.6 --- Fractal Analysis --- p.19 / Chapter 1.6.6.1 --- Background and Origin of Fractal Analysis --- p.19 / Chapter 1.6.6.2 --- Use of Fractal Analysis in Pharmaceutical Research --- p.20 / Chapter 1.6.6.3 --- Methods for fractal analysis --- p.21 / Chapter 1.6.7 --- Atomic Force Microscopy --- p.23 / Chapter 1.6.7.1 --- Background of Atomic Force Microscopy --- p.23 / Chapter 1.6.7.2 --- Characterization of Surface Topography by Atomic Force Microscopy --- p.23 / Chapter 1.6.7.3 --- Measurement of Interaction Forces by Colloid Probe 226}0Ø Microscopy --- p.25 / Chapter 1.6.7.4 --- Use of Atomic Force Microscopy in Pharmaceutical Research --- p.27 / Chapter Chapter Two --- Materials and Methods / Chapter 2.1. --- Materials --- p.30 / Chapter 2.2. --- Equipment --- p.31 / Chapter 2.3. --- Methods --- p.33 / Chapter 2.3.1. --- Powder Preparation --- p.33 / Chapter 2.3.1.1 --- Preparation of Salbutamol Sulphate Samples --- p.33 / Chapter 2.3.1.2 --- Preparation of Disodium Cromoglycate Samples --- p.33 / Chapter 2.3.1.3 --- Preparation of ß-Galactosidase (BG) Samples --- p.34 / Chapter 2.3.2. --- Determination of Aerosol Performance --- p.35 / Chapter 2.3.3. --- Determination of Protein Activity for BG Samples --- p.36 / Chapter 2.3.3.1. --- Enzyme Assay Procedure --- p.37 / Chapter 2.3.3.2. --- Calculation of Enzyme Activity --- p.38 / Chapter 2.3.3.3. --- Determination of Enzyme Activity Retained in Spray-dried Samples --- p.38 / Chapter 2.3.4. --- Physicochemical Characterization of Particles --- p.39 / Chapter 2.3.4.1. --- Scanning Electron Microscopy --- p.39 / Chapter 2.3.4.2. --- Particle Density Determination --- p.39 / Chapter 2.3.4.3. --- Particle Size Analysis --- p.40 / Chapter 2.3.4.4. --- Thermal analysis --- p.41 / Chapter 2.3.4.5. --- Powder X-ray Diffraction --- p.42 / Chapter 2.3.4.6. --- Surface Area Determination --- p.42 / Chapter 2.3.4.7. --- Surface Composition Characterization --- p.43 / Chapter 2.3.4.8. --- Surface Tension Measurement --- p.44 / Chapter 2.3.4.9. --- Inverse Gas Chromatography --- p.45 / Chapter 2.3.4.9.1. --- Calculation of Standard Free Energy of Adsorption --- p.46 / Chapter 2.3.4.9.2. --- Calculation of Dispersive Component of Surface Free Energy --- p.47 / Chapter 2.3.4.9.3. --- Determination of Specific Interactions and Associated Acid-Base Properties --- p.48 / Chapter 2.3.4.10. --- Fractal Analysis --- p.49 / Chapter 2.3.4.11. --- Atomic Force Microscopy --- p.49 / Chapter Chapter Three --- Results / Chapter 3.1. --- In vitro Aerosol Performance --- p.52 / Chapter 3.2. --- Enzyme Activity Retained in BG Samples --- p.55 / Chapter 3.3. --- Scanning Electron Microscopy (SEM) --- p.56 / Chapter 3.3.1. --- SEM of Salbutamol Sulphate Formulations --- p.56 / Chapter 3.3.2. --- SEM of DSCG Formulations --- p.59 / Chapter 3.3.3. --- SEM of BG Formulations --- p.61 / Chapter 3.4. --- Density Measurements --- p.65 / Chapter 3.4.1. --- Densities of Salbutamol Sulphate Formulations --- p.65 / Chapter 3.4.2. --- Densities of DSCG Formulations --- p.66 / Chapter 3.4.3. --- Densities of BG Formulations --- p.67 / Chapter 3.5. --- Particle Size Analysis by Laser Diffraction --- p.68 / Chapter 3.5.1. --- Volume Mean Diameter Measurements --- p.68 / Chapter 3.5.2. --- Particle Size Distributions and Dispersion Patterns of Formulations --- p.70 / Chapter 3.6. --- Thermal Analysis --- p.75 / Chapter 3.7. --- Powder X-ray Diffraction --- p.80 / Chapter 3.8. --- Surface Area Measurements --- p.84 / Chapter 3.9. --- Surface Composition Characterization --- p.85 / Chapter 3.9.1. --- Surface Composition of Salbutamol Sulphate Formulations --- p.85 / Chapter 3.9.2. --- Surface Composition of DSCG Formulations --- p.88 / Chapter 3.9.3. --- Surface Composition of BG/BSA Formulations --- p.89 / Chapter 3.10. --- Surface Tension Measurements --- p.91 / Chapter 3.11. --- Inverse Gas Chromatography --- p.92 / Chapter 3.12. --- Fractal Analysis --- p.93 / Chapter 3.13. --- Atomic Force Microscopy --- p.94 / Chapter Chapter Four --- Discussion / Chapter 4.1. --- Influence of BSA on Aerosol Performance and Protein Integrity --- p.98 / Chapter 4.2. --- Influence of BSA on Physicochemical Properties of Particles --- p.98 / Chapter 4.2.1. --- Influence of BSA on surface corrugation --- p.98 / Chapter 4.2.2. --- Influence of BSA on particle size and dispersion behavior --- p.99 / Chapter 4.2.3. --- Influence of BSA on crystallinity and thermal properties of particles --- p.100 / Chapter 4.2.4. --- Influence of BSA on surface energetics of particles --- p.100 / Chapter 4.3. --- Relationship between Surface Corrugation and Aerosol Performance --- p.101 / Chapter 4.4. --- Mechanism of Surface Modification for BSA on Spray-dried Particles --- p.103 / Chapter Chapter Five --- Conclusions and Future Work / Chapter 5.1. --- Conclusions --- p.106 / Chapter 5.1.1. --- General Aerosolization-Enhancing Effect of BSA --- p.106 / Chapter 5.1.2. --- Surface Modifying Effect of BSA --- p.106 / Chapter 5.1.3. --- Relationship between Surface Corrugation and Aerosol Performance --- p.106 / Chapter 5.2. --- Future Work --- p.107 / References --- p.108