Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
High Solid Dispersions
Download High Solid Dispersions full books in PDF, epub, and Kindle. Read online High Solid Dispersions ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis High Solid Dispersions by : Michel Cloitre
Download or read book High Solid Dispersions written by Michel Cloitre and published by Springer Science & Business Media. This book was released on 2010-10-28 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: From Polymers to Colloids: Engineering the Dynamic Properties of Hairy Particles, by D. Vlassopoulos and G. Fytas * Nonlinear Rheological Properties of Dense Colloidal Dispersions Close to a Glass Transition Under Steady Shear, by M. Fuchs * Micromechanics of Soft Particle Glasses, by R. T. Bonnecaze and M. Cloitre * Quantitative Imaging of Concentrated Suspensions Under Flow, by L. Isa, R. Besseling, A. B. Schofield and W. C. K. Poon * Soft and Wet Materials: From Hydrogels to Biotissues, by J. P. Gong and Y. Osada
Book Synopsis High Solid Dispersions by : Michel Cloitre
Download or read book High Solid Dispersions written by Michel Cloitre and published by Springer. This book was released on 2011-04-08 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: From Polymers to Colloids: Engineering the Dynamic Properties of Hairy Particles, by D. Vlassopoulos and G. Fytas * Nonlinear Rheological Properties of Dense Colloidal Dispersions Close to a Glass Transition Under Steady Shear, by M. Fuchs * Micromechanics of Soft Particle Glasses, by R. T. Bonnecaze and M. Cloitre * Quantitative Imaging of Concentrated Suspensions Under Flow, by L. Isa, R. Besseling, A. B. Schofield and W. C. K. Poon * Soft and Wet Materials: From Hydrogels to Biotissues, by J. P. Gong and Y. Osada
Book Synopsis Amorphous Solid Dispersions by : Navnit Shah
Download or read book Amorphous Solid Dispersions written by Navnit Shah and published by Springer. This book was released on 2014-11-21 with total page 699 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a comprehensive guide on the theory and practice of amorphous solid dispersions (ASD) for handling challenges associated with poorly soluble drugs. In twenty-three inclusive chapters, the book examines thermodynamics and kinetics of the amorphous state and amorphous solid dispersions, ASD technologies, excipients for stabilizing amorphous solid dispersions such as polymers, and ASD manufacturing technologies, including spray drying, hot melt extrusion, fluid bed layering and solvent-controlled micro-precipitation technology (MBP). Each technology is illustrated by specific case studies. In addition, dedicated sections cover analytical tools and technologies for characterization of amorphous solid dispersions, the prediction of long-term stability, and the development of suitable dissolution methods and regulatory aspects. The book also highlights future technologies on the horizon, such as supercritical fluid processing, mesoporous silica, KinetiSol®, and the use of non-salt-forming organic acids and amino acids for the stabilization of amorphous systems. Amorphous Solid Dispersions: Theory and Practice is a valuable reference to pharmaceutical scientists interested in developing bioavailable and therapeutically effective formulations of poorly soluble molecules in order to advance these technologies and develop better medicines for the future.
Book Synopsis Pharmaceutical Amorphous Solid Dispersions by : Ann Newman
Download or read book Pharmaceutical Amorphous Solid Dispersions written by Ann Newman and published by John Wiley & Sons. This book was released on 2015-03-09 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a roadmap from early to late stages of drug development, this book overviews amorphous solid dispersion technology – a leading platform to deliver poorly water soluble drugs, a major hurdle in today’s pharmaceutical industry. • Helps readers understand amorphous solid dispersions and apply techniques to particular pharmaceutical systems • Covers physical and chemical properties, screening, scale-up, formulation, drug product manufacture, intellectual property, and regulatory considerations • Has an appendix with structure and property information for polymers commonly used in drug development and with marketed drugs developed using the amorphous sold dispersion approach • Addresses global regulatory issues including USA regulations, ICH guidelines, and patent concerns around the world
Book Synopsis Pharmaceutical Solid Dispersion Technology by : Muhammad J. Habib
Download or read book Pharmaceutical Solid Dispersion Technology written by Muhammad J. Habib and published by CRC Press. This book was released on 2000-10-05 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has not, until now, been a single up-to-date volume to provide those in drug R&D with practical information on all aspects of solid dispersion technology for drugs. This forthcoming volume finally provides such a guide and reference. The unified presentation by a team of specialists in this field is designed for practical application. Theoretical concepts are covered for a fuller understanding of current techniques. All significant recent developments are included.
Book Synopsis Recent Progress in Solid Dispersion Technology by : Kohsaku Kawakami
Download or read book Recent Progress in Solid Dispersion Technology written by Kohsaku Kawakami and published by MDPI. This book was released on 2019-10-01 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amorphous solid dispersion (ASD) is a powerful formulation technology to improve oral absorption of poorly soluble drugs. Despite their being in existence for more than half a century, controlling ASD performance is still regarded as difficult because of ASD’s natural non-equilibrium. However, recent significant advances in ASD knowledge and technology may enable a much broader use of ASD technology. This Special Issue, which includes 3 reviews and 6 original articles, focuses on recent progresses in ASD technology in hopes of helping to accelerate developmental studies in the pharmaceutical industry. In striving for a deep understanding of ASD non-equilibrium behavior, the Special issue also delves into and makes progress in the theory of soft-matter dynamics.
Book Synopsis Solubility enhancement of poorly water-soluble drugs by solid dispersion by : Adela Kalivoda
Download or read book Solubility enhancement of poorly water-soluble drugs by solid dispersion written by Adela Kalivoda and published by Cuvillier Verlag. This book was released on 2012-06-25 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary Solid dispersions are a promising approach for controlled release drug delivery systems as both the bioavailability enhancement of poorly water-soluble drugs as well as the sustained release of water-soluble drugs are possible to optimize their in vivo performance. Different methods for the manufacture of solid dispersion systems have been introduced in literature. In the present work, two methods are compared: hot-melt extrusion and ultrasound-assisted compaction technique. Various carrier systems and drugs with different physicochemical properties are applied to investigate the feasibility of the technologies for pharmaceutical formulation. The formulations are compared to the corresponding untreated physical blends of the components regarding their solid state structure and dissolution behavior to assess the effect of the manufacturing technique. Ultrasound-assisted compaction technique improves the initial dissolution rate of fenofibrate, a poorly water-soluble model drug. The crystalline API is partially converted into its amorphous state. As equivalent results can be achieved if the polymers are added directly to the dissolution medium, the dissolution enhancement is attributed to an improved wettability of the drug. A statistical design of experiments is employed to investigate the effect of the process parameters on the results. Difficulties are encountered in the determination of process parameters which result in an optimal outcome. The process is very sensitive to the smallest changes of settings, for example of the position of the sonotrode. Additionally, the delivery of ultrasound energy is inhomogeneous. There is no or only insufficient user control of these parameters available. Furthermore, the duration of ultrasound energy delivery which is identified as a crucial parameter cannot be set by the user. The variable factors ultrasound energy, pressure of the lower piston and pressure of the upper piston affect the defined responses in the opposite direction. Hence, there are no settings which result in a satisfactory outcome. A strong influence of the material characteristics on the process is observed leading to a batch to batch variability. Due to an insufficient reproducibility of results, the application of the technology cannot be recommended in its current state in the pharmaceutical formulation development and/or production. Improvements in homogeneity of energy delivery, process monitoring, user control and amount of leakage are mandatory for an acceptable performance and a future application in the pharmaceutical sector. The polymers COP, HPMC and PVCL-PVAc-PEG are well suitable as carriers for hot-melt extruded formulations of fenofibrate. All three extrudates are amorphous one-phase systems with the drug molecularly dispersed in the polymer. The enhancement of the initial dissolution rate and the maximum concentration level achieved are dependent on the applied carrier system. Supersaturation levels of up to 12.1 times are reached which are not stable due to recrystallization processes. The application of blends of polymers as carriers reduces the decrease rate after cmax. Because of water absorption and polymer relaxation, the overall dissolution performance decreases with increasing storage times which can be avoided through an optimization of the packaging. If oxeglitazar is used as API, the initial dissolution rate of the extrudates is below that of the untreated drug, with the exception of the ternary blend of COP, HPMC and oxeglitazar which shows a substance-specific super-additive effect. In contrast to the other extrudates, the formulation of PVCL-PVAc-PEG and oxeglitazar does not form a molecularly dispersed solid solution of the drug in the carrier. Instead, an amorphous two-phase system is present. No changes are observed after storage, presumably due to higher glass transition temperatures of the hot-melt extruded systems which are considerably above those of the corresponding fenofibrate extrudates. With felodipine as API, the dissolution profile is enhanced with COP as single carrier. If HPMC or PVCL-PVAc-PEG is used as single or additional polymeric carriers, the dissolution is equivalent (HPMC) or lower (PVCL-PVAc-PEG) than that of the pure drug although molecularly disperse systems are present in all cases. Out of the two investigated methods only hot-melt extrusion is a suitable technology to manufacture solid dispersions with an improved dissolution behavior. The dissolution profile of the extrudates can be influenced by adding polymers with differing physicochemical characteristics. Predictions on the dissolution behavior of the extrudates with polymeric blends as carriers can be made if there is knowledge on the dissolution profiles of the corresponding single polymeric extrudates. Due to substance-specific effects, the results are not transferable from drug to drug. Even so, the data are promising as the release behavior of the manufactured extrudates can be easily modified and readily adapted to one's needs. Further research will have to be conducted to verify the concept and the relevance of the results in vivo. Zusammenfassung Feste Dispersionen sind ein vielversprechender Ansatz zur Herstellung von Drug Delivery-Systemen mit kontrollierter Wirkstofffreisetzung, da sie sowohl die Bioverfügbarkeit schlecht wasserlöslicher Arzneistoffe verbessern als auch die Freisetzung gut wasserlöslicher Arzneistoffe verzögern können und so deren in vivo Verhalten optimieren. Verschiedene Herstellungsmethoden wurden in der Literatur vorgestellt. In der vorliegenden Arbeit werden zwei Technologien miteinander verglichen: Schmelzextrusion und Ultraschall gestützte Verpressung (USAC). Verschiedene Trägersysteme und Arzneistoffe mit unterschiedlichen physikochemischen Eigenschaften werden untersucht, um die Einsatzmöglichkeit im pharmazeutischen Bereich zu überprüfen. Die Struktur der hergestellten Systeme und deren Freisetzungsverhalten werden mit den physikalischen Mischungen der Komponenten verglichen, um den Einfluss der Formulierung zu bestimmen. Durch USAC wird die initiale Freisetzungsrate von Fenofibrat, einem schlecht wasserlöslichen Modellarzneistoff, verbessert. Eine teilweise Umwandlung vom kristallinen in den amorphen Zustand tritt auf. Vergleichbare Ergebnisse werden bei einer Polymerzugabe zum Freisetzungsmedium erreicht; daher wird davon ausgegangen, dass vor allem eine verbesserte Benetzbarkeit des Arzneistoffs eine Rolle spielt. Mittels statistischer Versuchsplanung wird der Einfluss der verschiedenen Prozessparameter untersucht. Die Einstellung der Prozessparameter, um ein optimales Ergebnis zu erhalten, gestaltet sich schwierig. Der Prozess reagiert auf kleinste Veränderungen, zum Beispiel der Position der Sonotrode, überaus sensitiv. Außerdem wird die Ultraschallenergie nicht homogen übertragen. Die Kontrolle dieser Parameter durch den Anwender ist nicht oder nur unzureichend möglich. Ebenso kann die Dauer der Ultraschallapplizierung, die essentiell für den Prozess ist, nicht eingestellt werden. Die Prozessparameter Ultraschallenergie, Unterstempeldruck und Sonotrodendruck beeinflussen die Zielgrößen in entgegengesetzter Richtung. Daher gibt es keine Einstellung, die für alle Zielgrößen optimale Ergebnisse liefert. Zusätzlich ist der Prozess stark abhängig von den Eigenschaften des verwendeten Materials: Die Verwendung unterschiedlicher Polymerchargen macht eine Anpassung der Prozessparameter notwendig, um vergleichbare Ergebnisse zu erhalten. Eine ausreichende Reproduzierbarkeit der Ergebnisse für einen Einsatz dieser Technologie in Formulierungsentwicklung oder Produktion ist nicht gegeben. Eine homogene Ultraschallenergiezufuhr sowie Verbesserungen der Prozessüberwachung, der Benutzerkontrolle und eine Verminderung der austretenden Materialmenge sind für eine akzeptable Leistung und eine zukünftige Anwendung im pharmazeutischen Bereich zwingend erforderlich. Die Polymere COP, HPMC, PVCL-PVAc-PEG sind für eine Freisetzungsverbesserung von Fenofibrat mittels Schmelzextrusion geeignet. Es liegen einphasige, molekulardisperse feste Lösungen vor. Abhängig von der Trägersubstanz wird die initiale Freisetzungsrate unterschiedlich stark erhöht, ebenso die maximale Konzentration des Arzneistoffes in Lösung. Eine bis zu 12.1-fache Übersättigung wird erreicht, die aufgrund von Rekristallisationsprozessen nicht stabil ist. Der Einsatz von polymeren Mischungen reduziert die Geschwindigkeit des Konzentrationsabfalls. Die Absorption von Wasser und Relaxationseffekte vermindern die Freisetzungserhöhung mit zunehmender Lagerdauer; dieser Entwicklung kann durch eine Optimierung des Packmittels entgegengewirkt werden. Wird der ebenfalls schwer wasserlösliche Arzneistoff Oxeglitazar verwendet, so ist die initiale Freisetzungsrate der Extrudate der des reinen Arzneistoffs unterlegen, mit Ausnahme der ternären Mischung von COP, HPMC und Oxeglitazar, die einen substanzspezifischen überadditiven Effekt aufweist. PVCL-PVAc-PEG-Oxeglitazar-Extrudate bilden im Gegensatz zu den übrigen Formulierungen keine molekulardisperse feste Lösung, sondern ein amorphes Zwei-Phasen-System. Eine Veränderung während der Lagerzeit wird nicht beobachtet, vermutlich aufgrund der höheren Glasübergangstemperaturen dieser Systeme. Lediglich das Freisetzungsprofil von COP-Felodipin-Extrudaten ist verbessert. Gegenüber dem reinen Arzneistoff ist die Freisetzung der übrigen Extrudate vergleichbar (HPMC) oder verringert (PVCL-PVAc-PEG), obwohl auch hier molekulardisperse Systeme vorliegen. Von den beiden untersuchten Technologien ist lediglich die Schmelzextrusion geeignet, um feste Dispersionen mit einem verbesserten Freisetzungsverhalten herzustellen. Das Freisetzungsprofil der Extrudate kann durch den Zusatz von Polymeren mit unterschiedlichen Eigenschaften optimiert und vorhergesagt werden, wenn das Freisetzungsprofil der Einzelpolymer-Extrudate bekannt ist. Die Ergebnisse sind aufgrund von substanzspezifischen Effekten nicht von Arzneistoff auf Arzneistoff übertragbar. Nichtsdestotrotz sind die Erkenntnisse dieser Arbeit vielversprechend, da gezeigt wird, dass das Freisetzungsprofil der Extrudate leicht beeinflusst und an spezifische Anforderungen angepasst werden kann. Weitere Untersuchungen sind notwendig, um das Konzept und die Relevanz der Ergebnisse in vivo zu überprüfen.
Book Synopsis Particle Breakage by : Agba D. Salman
Download or read book Particle Breakage written by Agba D. Salman and published by Elsevier. This book was released on 2007-11-01 with total page 1240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle breakage is an important process within a wide range of solids processing industries, including pharmaceuticals, food, agricultural and mining. Breakage of particles can be defined as intentional and unintentional, depending on whether it is desired or not. Through understanding of the science and underlying mechanisms behind this phenomenon, particle breakage can be either minimised or encouraged within an efficient and effective process. Particle Breakage examines particle breakage at three different length scales, ranging from single particle studies through groups of particles and looking at solid processing steps as a whole. This book is the widest ranging book in the field and includes the most up-to-date techniques such as Distinct Element Method (DEM), Monte Carlo simulations and Population Balance Equations (PBE). This handbook provides an overview of the current state-of-the- art and particle breakage. From the small scale of a single particle, to the study of whole processes for breakage; both by experimental study and mathematical modelling. * Covering a wide range of subjects and industrial applications * Allows the reader an understanding of the science behind engineered breakage processes * Giving an unrestrictive and interdisciplinary approach
Download or read book Electrospinning written by Seema Agarwal and published by Walter de Gruyter GmbH & Co KG. This book was released on 2016-03-21 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on basic aspects of nano/microfibers made by electrospinning with details on spinning recipes, characterization techniques and chemistry of the polymers in use. The basic understanding provided in the book, is useful for producing 1D and 3D fibrous structures with specific properties for applications, e.g. textiles, membranes, reinforcements, catalysis, filters or biomedical uses. Students and practitioners will find great value in the step by step instructions how to manufacture nanofibers. - Electrospinning equipment - History of electrospinning and nanofibers -characterization-fundamentals of electrospun fibers - Ready-made recipes for spinning solutions - Conditions for the productions of highly diverse fiber morphologies and arrangements - Chemistry of fiber forming materials
Book Synopsis The Preparation of Dispersions in Liquids by : H.N. Stein
Download or read book The Preparation of Dispersions in Liquids written by H.N. Stein and published by CRC Press. This book was released on 2020-07-24 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work details the preparation of dispersions in liquids. It sets out to bridge the gap in information for the chemist who is not applications oriented and the chemical engineer who needs to solve problems in the field based on theoretical methods of dispersions of solids, liquids and gases. Insights are provided into many topics, including the transportation and handling of finely divided soils or highly viscous liquids; the reactions between reactants dissolved in immiscible phases; the formation of porous materials; and filtration.
Author :Robert O. Williams III Publisher :Springer Science & Business Media ISBN 13 :9781461411444 Total Pages :648 pages Book Rating :4.4/5 (114 download)
Book Synopsis Formulating Poorly Water Soluble Drugs by : Robert O. Williams III
Download or read book Formulating Poorly Water Soluble Drugs written by Robert O. Williams III and published by Springer Science & Business Media. This book was released on 2011-12-04 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is intended to provide the reader with a breadth of understanding regarding the many challenges faced with the formulation of poorly water-soluble drugs as well as in-depth knowledge in the critical areas of development with these compounds. Further, this book is designed to provide practical guidance for overcoming formulation challenges toward the end goal of improving drug therapies with poorly water-soluble drugs. Enhancing solubility via formulation intervention is a unique opportunity in which formulation scientists can enable drug therapies by creating viable medicines from seemingly undeliverable molecules. With the ever increasing number of poorly water-soluble compounds entering development, the role of the formulation scientist is growing in importance. Also, knowledge of the advanced analytical, formulation, and process technologies as well as specific regulatory considerations related to the formulation of these compounds is increasing in value. Ideally, this book will serve as a useful tool in the education of current and future generations of scientists, and in this context contribute toward providing patients with new and better medicines.
Book Synopsis Mechanical Production of Nanoparticles in Stirred Media Mills by :
Download or read book Mechanical Production of Nanoparticles in Stirred Media Mills written by and published by Cuvillier Verlag. This book was released on 2007-06-13 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology applications in the pharmaceutical, materials, and chemical industries has renewed interest in the use of wet grinding in stirred media mills for the production of nanoparticles with controlled microstructure. Quite recently it is possible to mill particles down to the size range of 10 nm. However, challenges arise in the production of sub-micron particles that are, in part, due to colloidal surface forces influencing slurry stability and rheology. In this work experiments are performed on a well characterized model system of monodisperse primary nanoparticles that are salt destabilized and aggregated under various milling conditions. Perikinetic and orthokinetic aggregation are measured, with the latter in a laminar shear flow as well as in a stirred media mill, to examine the effects of colloidal stability and flow on the aggregation process. The agglomeration kinetics are measured using dynamic light scattering (DLS) as a function of electrolyte concentrations. Further information on the agglomeration process and the structure of the agglomerates are also obtained from small angle neutron scattering (SANS) and rheo-optical light scattering (ROA) experiments both at rest and under flow. Theoretical predictions for the colloidal stability from independently measured particle and solution properties compare well with the experimental results. Orthokinetic aggregation is observed to result in faster aggregation and denser agglomerates. Because of the high industrial demand for nanoparticles in organic media the study was extended to non-aqueous systems. Electrostatic stabilization requires a sufficiently high surface charge leading to a steeply decaying surface potential. These conditions can be met by solvents of medium dielectric constant (i.e. values larger than about 15-20), e.g. alcohols. In these media the particles may carry a high surface charge and the solubility of salts will be sufficient to enable a high repulsive barrier. It is shown that stable suspensions with high ζ-potentials can be achieved for alumina in ethanol with elecrostatic stabilization. Milling studies with electrostatic stabilization showed that the size of the primary particles is conspicuously smaller than the size of the particles milled under the same conditions in the aqueous phase. However, the media wear has a negative influence on the stability of the suspension since the ionic strengths in organic solvents are much lower. Milling experiments with steric stabilization in organic solvents produced larger primary particle sizes than with electrostatic conditions. The polymer layer around the particles seems to adsorb part of the grinding energy during the impact of two grinding beads and cushions the comminution. However, media wear has in contrast to the electrostatic stabilized particles in organic solvents no influence on the stability of the suspension. An important question is whether the mechano-chemical activation which was observed in aqueous media is crucial to obtain nanoparticles. Differential Scanning Calorimetry (DSC) and X-ray diffraction (XRD) measurements showed no mechano-chemical changes during milling in ethanol and toluene. In the aqueous phase the stabilization mechanism has no influence on the amount of hydroxide phase. A protecting polymer cover around the particles does not prevent the mechano-chemical changes.
Book Synopsis Eco-Friendly Waterborne Polyurethanes by : Ram K. Gupta
Download or read book Eco-Friendly Waterborne Polyurethanes written by Ram K. Gupta and published by CRC Press. This book was released on 2022-01-25 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: The polyurethane industry is among the fastest growing, with polyurethanes used in consumer as well as industrial sectors. Waterborne polyurethanes (WPUs) exhibit many advantages over conventional volatile organic compounds (VOCs) based polyurethanes and have emerged as an environmentally friendly alternative. WPUs offer an opportunity to use sustainable raw materials to produce environmentally sustainable polymers, particularly, polyols derived from vegetable oils. Eco-Friendly Waterborne Polyurethanes: Synthesis, Properties, and Applications provides state-of-the-art knowledge of the synthesis, application, and property enhancement of WPUs. Covers various types of eco-friendly materials and technologies used to synthesize WPUs Presents an overview and applications of WPUs in several advanced research areas Provides fundamentals of synthetic processes and their chemistries for specific applications Elaborates on advanced approaches used to convert renewable resources into polymers Offers new direction to scientists, researchers, and students to better understand the chemistry, technologies, and applications Written for polymer chemists, materials scientists, and other researchers and industry, this book serves as a comprehensive reference for readers interested in the development and application of sustainable polymers.
Book Synopsis Rheology and Fourier-Transform Rheology on Water-Based Systems by : Christopher Klein
Download or read book Rheology and Fourier-Transform Rheology on Water-Based Systems written by Christopher Klein and published by Logos Verlag Berlin GmbH. This book was released on 2008 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of shear fields on water-based systems was investigated within this thesis. The non-linear rheological behaviour of spherical and rod-like particles was examined with Fourier-Transform rheology under LAOS conditions. As a model system for spherical particles two different kinds of polystyrene disper- sions, with a solid content higher than 0.3 each, were synthesised within this work. Due to the differences in polydispersity and Debye-length, differences were also found in the rheology. In the FT-rheology both kinds of dispersions showed a similar rise in the intensities of the magnitudes of the odd higher harmonics, which were predicted by a model. The, in some cases additionally appearing second harmonics, were not predicted. A novel method to analyse the time domain signal was developed, that splits the time domain signal up in four characteristic functions. Those characteristic functions correspond to rheological phenomena. In some cases the intensities of the Fourier components can interfere negatively. FD-virus particles were used as a rod-like model system, which already shows a highly non-linear behaviour at concentrations below 1. % wt. Predictions for the dependence of the higher harmonics from the strain amplitude described the non-linear behaviour well at large, but no so good at small strain amplitudes. Ad- ditionally the trends of the rheological behaviour could be described by a theory for rod-like particles. An existing rheo-optical set-up was enhanced by reducing the background birefringence by a factor of 20 and by increasing the time resolution by a factor of 24. Additionally a combination of FT-rheology and rheo-optics was achieved. The influence of a constant shear field on the crystallisation process of zinc oxide in the presence of a polymer was examined. The crystallites showed a reduction in length by a factor of 2. The directed addition of polymers in combi- nation with a defined shear field can be an easy way for a defined change of the form of crystallites.
Book Synopsis Pressure-Sensitive Adhesives and Applications by : Istvan Benedek
Download or read book Pressure-Sensitive Adhesives and Applications written by Istvan Benedek and published by CRC Press. This book was released on 2004-02-03 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pressure-Sensitive Adhesives and Applications, Second Edition explains how pressure-sensitive adhesives (PSAs) work, why they are used, and the technology used to manufacture them. This second edition features the latest developments in the field. Dr. Benedek discusses the factors that affect the rheology and special flow characteristics responsible for the adhesivity of liquid and solid PSAs. His book explores the viscoelastic behavior of PSAs, and compares them to plastics, rubbers, and polymers properties and examines the parameters that influence the conversion process of PSAs from the coating of carrier materials to the properties of the final laminate. The author covers adhesion/cohesion balance, time-temperature dependence of pressure sensitivity, chemical composition, coating properties, and coating processes affect the adhesive properties of PSA and their end products and how application-specific performance indices are used to determine the formulation and manufacture of raw materials. In addition, up-to-date coating machines, converting technology, and environmental considerations in the manufacture of PSA final products as well as industry-specific methods of testing for quality assurance and control are discussed. Pressure-Sensitive Adhesives and Applications, Second Edition combines the theoretical basis of pressure sensitivity with the practical aspects of manufacturing, testing, and use of PSAs. Readers are offered an exhaustive as well as comparative look at the engineering of plastics, adhesives, and pressure-sensitives, resulting in an indispensable, up-to-date reference for adhesive and polymer chemists and technologists.
Book Synopsis Adhesion Science and Technology by : Lieng-Huang Lee
Download or read book Adhesion Science and Technology written by Lieng-Huang Lee and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first ACS Adhesion Symposium was held in Washington, D.C., September 1971. During the four years since that meeting, much interest in adhesion has been generated among six divisions of the American Chemical Society. Then, in 1974, the Macromolecular Secretariat appointed me to work closely with the six Session chairmen in organizing this Symposium on Science and Technology of Adhesion. Needless to say, the success of the Symposium which took place between April 7 and 10, 1975 in Philadelphia, Pa., is due to their excellent cooperation and the enthusiastic response of con tributors. As originally planned, each division was responsible for one session, and most of the papers, including several late con tributions, are published in these two volumes of proceedings. During the Symposium, we held a banquet in honor of Professor Herman Mark in celebration of his eightieth birthday. His Plenary Lecture and the Symposium Address by Professor Murray Goodman are published in full at the beginning of the first volume. I thank Professors Mark and Goodman for their excellent presentations on this memorable occasion.
Book Synopsis Melt Extrusion by : Michael A. Repka
Download or read book Melt Extrusion written by Michael A. Repka and published by Springer Science & Business Media. This book was released on 2013-10-11 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides readers with the basic principles and fundamentals of extrusion technology and a detailed description of the practical applications of a variety of extrusion processes, including various pharma grade extruders. In addition, the downstream production of films, pellets and tablets, for example, for oral and other delivery routes, are presented and discussed utilizing melt extrusion. This book is the first of its kind that discusses extensively the well-developed science of extrusion technology as applied to pharmaceutical drug product development and manufacturing. By covering a wide range of relevant topics, the text brings together all technical information necessary to develop and market pharmaceutical dosage forms that meet current quality and regulatory requirements. As extrusion technology continues to be refined further, usage of extruder systems and the array of applications will continue to expand, but the core technologies will remain the same.
