Download or read book Solubility and Solubilization in Aqueous Media written by Samuel Hyman Yalkowsky and published by Acs Professional Reference Boo. This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims to provide the reader with a working knowledge of the various means of controlling the solubility or dissolution rate of a drug or other solute in an aqueous medium. The book begins with the factors which govern solubility in general and then looks at aqueous solubility in particular, including the properties of liquid mixtures and the thermodynamics of solutions formed from mixing two components. The bulk of the book is then devoted to techniques for altering solubility and dissolution rate of organic compounds in aqueous media. It discusses in detail the most commonly used solubility enhancers: buffers, cosolvents, surfactants, and complexants. Each chapter is self-contained and emphasizes the details for applying the techniques.
Download or read book Poorly Soluble Drugs written by Gregory K. Webster and published by CRC Press. This book was released on 2017-01-06 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first text to provide a comprehensive assessment of the application of fundamental principles of dissolution and drug release testing to poorly soluble compounds and formulations. Such drug products are, vis-à-vis their physical and chemical properties, inherently incompatible with aqueous dissolution. However, dissolution methods are required for product development and selection, as well as for the fulfillment of regulatory obligations with respect to biopharmaceutical assessment and product quality understanding. The percentage of poorly soluble drugs, defined in classes 2 and 4 of the Biopharmaceutics Classification System (BCS), has significantly increased in the modern pharmaceutical development pipeline. This book provides a thorough exposition of general method development strategies for such drugs, including instrumentation and media selection, the use of compendial and non-compendial techniques in product development, and phase-appropriate approaches to dissolution development. Emerging topics in the field of dissolution are also discussed, including biorelevant and biphasic dissolution, the use on enzymes in dissolution testing, dissolution of suspensions, and drug release of non-oral products. Of particular interest to the industrial pharmaceutical professional, a brief overview of the formulation and solubilization techniques employed in the development of BCS class 2 and 4 drugs to overcome solubility challenges is provided and is complemented by a collection of chapters that survey the approaches and considerations in developing dissolution methodologies for enabling drug delivery technologies, including nanosuspensions, lipid-based formulations, and stabilized amorphous drug formulations.
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 656 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.
Download or read book Solubilization by Surface active Agents and Its Applications in Chemistry and the Biological Sciences written by Peter Howard Elworthy and published by . This book was released on 1968 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enhancement of Solubilization Bioavailability of Poorly Soluble Drug written by Amit Chaudhary and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this work is to improve the solubilization and bioavailability of poorly soluble drugs by using various approaches like physical, chemical and others modifications or techniques. The solubility of a solute is the maximum quantity of solute that can dissolve in a certain quantity of solvent or quantity of solution at a specified temperature. Solubility is one of the important parameter to achieve desired concentration of drug in systemic circulation for pharmacological response to be shown. Drug efficacy can be severely limited by poor aqueous solubility and some drugs also show side effects due to their poor solubility. There are many techniques which are used to enhance the aqueous solubility. The ability to increase aqueous solubility can thus be a valuable aid to increasing efficiency and/or reducing side effects for certain drugs. This is true for parenterally, topically and orally administered solutions. Physical modifications techniques like media milling/ nanocrystal technology, cryogenic technology, supercritical fluid process, modification of the crystal habit, complexation, micellar technologies, chemical modifications etc.
Download or read book The Experimental Determination of Solubilities written by G. T. Hefter and published by John Wiley & Sons. This book was released on 2003-08-01 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: * Guidelines are provided on the reliability of various methods, as well as information for selecting the appropriate technique. * Unique coverage of the whole range of solubility measurements. * Very useful for investigators interested in embarking upon solubility measurements.
Download or read book Poorly Soluble Drugs written by Gregory K. Webster and published by Jenny Stanford Publishing. This book was released on 2016-12-16 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first text to provide a comprehensive assessment of the application of fundamental principles of dissolution and drug release testing to poorly soluble compounds and formulations. Such drug products are, vis-à-vis their physical and chemical properties, inherently incompatible with aqueous dissolution. However, dissolution methods are required for product development and selection, as well as for the fulfillment of regulatory obligations with respect to biopharmaceutical assessment and product quality understanding. The percentage of poorly soluble drugs, defined in classes 2 and 4 of the Biopharmaceutics Classification System (BCS), has significantly increased in the modern pharmaceutical development pipeline. This book provides a thorough exposition of general method development strategies for such drugs, including instrumentation and media selection, the use of compendial and non-compendial techniques in product development, and phase-appropriate approaches to dissolution development. Emerging topics in the field of dissolution are also discussed, including biorelevant and biphasic dissolution, the use on enzymes in dissolution testing, dissolution of suspensions, and drug release of non-oral products. Of particular interest to the industrial pharmaceutical professional, a brief overview of the formulation and solubilization techniques employed in the development of BCS class 2 and 4 drugs to overcome solubility challenges is provided and is complemented by a collection of chapters that survey the approaches and considerations in developing dissolution methodologies for enabling drug delivery technologies, including nanosuspensions, lipid-based formulations, and stabilized amorphous drug formulations.
Download or read book Solubilities of Inorganic and Organic Substances written by Atherton Seidell and published by . This book was released on 1907 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solubilities of Inorganic and Organic Compounds A Compilation of Quantitative Solubility Data from the Periodical Literature written by Atherton Seidell and published by . This book was released on 1928 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Techniques of Solubilization of Drugs written by Samuel H. Yalkowsky and published by . This book was released on 1981 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Insoluble Drug Formulation written by Ron Liu and published by CRC Press. This book was released on 2000-09-30 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Delivering drugs in a water-insoluble formulation is a critical matter in therapeutic drug development. However, because a drug molecule has to be water soluble to be readily delivered to the cellular membrane while retaining its hydrophobic properties, issues surrounding water insolubility can postpone - or completely derail - important new drug development. Even much needed reformulation of currently marketed products can be significantly affected by these issues. This book systematically describes the techniques used for water-insoluble formulations, providing step-by-step guidance as well as scientific background on drug and water properties and how they contribute to solubilization and dissolution. A world-class team of experts discusses how these issues are viewed - and solved - by key industry and R&D institutions. This book provides a handy reference for pharmaceutical scientists in the handling of formulation issues related to water-insoluble drugs. In addition, this book may be useful to pharmacy and chemistry undergraduate students, and pharmaceutical and biopharmaceutical graduate students, to enhance their knowledge in the techniques of drug solubilization and dissolution enhancement.
Download or read book Solubilities of Inorganic and Organic Substances written by Atherton Seidell and published by . This book was released on 1911 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Solubility and Dissolution Behavior of 90SrF2 in Aqueous Media written by Harold Thomas Fullam and published by . This book was released on 1976 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drug solubility and bioavailability improvement Possible methods with emphasis on liquisolid systems formulation written by Jan Gajdziok and published by GRIN Verlag. This book was released on 2018-10-04 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Document from the year 2018 in the subject Pharmicology, grade: 1, , course: Pharmaceutical Technology, language: English, abstract: The aim of this book is to provide a brief but comprehensive overview on the issue of drug bioavailability improvement by preparation of a perspective dosage form – liquisolid systems. The introduction chapter about drug solubility and bioavailability is followed by a description of the general methods which could be used to improve drug bioavailability using approaches of chemistry, physical modification, and primarily pharmaceutical technology. Benefits and practical use of each method are documented by examples. The main part of the book is aimed at characterization and description of liquisolid systems (LSS) – perspective dosage form for bioavailability improvement. Elementary principles of LSS formulation are described in detail, e.g. how to perform a preformulation study; how to choose the correct type and amount of excipients; how to evaluate the dosage forms, etc. All the above mentioned principles are documented with practical examples. The book could be used as a textbook for students of natural, medical and pharmaceutical sciences as well as by researchers in this field or industrial area. Contemporary pharmacotherapy is characterized by the increasing amount of active substances that are only poorly soluble in water. This may lead to the limitation of their systemic absorption on oral administration which is closely related to the bioavailability. This category is estimated to include more than forty percent of active substances that are in general use. So far, this poor aqueous solubility has been improved by physical or chemical modification of the active substance. In general, such changes are very expensive and troublesome, often leading to problems in stability, marketing authorization process, or administration comfort of the particular drug. This is one of the reasons why modern pharmaceutical technology has focused on those dosage forms that can increase the bioavailability of some active substances while maintaining suitable stability and administration comfort. Several processes that improve solubility, respectively bioavailability have been described and published. These include micronization, nanocrystals, and formulation of solid dispersions. Only recently, a novel trend has appeared – to take advantage of good solubility of active substances in chosen solvents, that is, to use the active substances in a liquid phase.
Download or read book Handbook of Solubility Data for Pharmaceuticals written by Abolghasem Jouyban and published by CRC Press. This book was released on 2009-08-26 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aqueous solubility is one of the major challenges in the early stages of drug discovery. One of the most common and effective methods for enhancing solubility is the addition of an organic solvent to the aqueous solution. Along with an introduction to cosolvency models, the Handbook of Solubility Data for Pharmaceuticals provides an extensive datab
Download or read book Solubilities of Inorganic and Organic Substances written by Atherton Seidell and published by . This book was released on 1928 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
