Download or read book Thermodynamic Modeling of Binary and Ternary Systems of Interest to Gas Antisolvent Precipitation written by Dana Marie McDiffett and published by . This book was released on 2004 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: paracetamol.
Download or read book Thermodynamic Modeling of Binary and Ternary Systems of Interest to Gas Antisolvent Precipitation written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: CO2 is a poor solvent for polar and complex molecules. The batch process known as GAS precipitation exploits the ability of CO2 to function as an antisolvent. CO2 is dissolved at low temperatures and moderate pressures into an organic solvent into which a solute has been dissolved. The liquid phase is expanded, reducing the solvent power, and causing precipitation of the solute. In this way, thermally-labile pharmaceutical compounds can be purified from organic solutions as very fine, uniform particles. In a simple (1) antisolvent -- (2) solvent -- (3) solute GAS system, solid-vapor-liquid equilibrium (SVLE) exists at the point of precipitation. The solubilities of acetaminophen in CO2-expanded ethanol, x3, and of acetaminophen in the equilibrium vapor phase, y3, were predicted using a three-component, ternary-phase Mathcad code. The Peng-Robinson equation of state was used to represent the fluid phases and a simple fugacity expression was used to represent the solid phase. Binary interaction parameters for the CO2-ethanol and ethanol-acetaminophen pairs, k12=0.0890 and k23=0.0099, were regressed from literature solubility data. The binary interaction parameter for the CO2-acetaminophen pair, k13=0.2614, was regressed using solubility data taken using a static equilibrium apparatus. The vapor phase mole fraction of acetaminophen in CO2 at 323K ranges from 10-6 to 10-4 over the pressure range 1500 psi to 4000 psi. The Peng-Robinson equation of state model is unable to capture the solubility behavior, but the data are adequately fit using a non-predictive density-based correlation. A sensitivity analysis conducted on the SVLE model to determine the effect of the binary interaction parameters on the prediction of x3 indicates that a poor fit for k13 does not prevent making an adequate prediction for the change in x3 with increasing pressure. At a given temperature, the solubility of acetaminophen in CO2-expanded ethanol decreases with pressure, indicating tha.
Download or read book High pressure Phase Equilibria and Thermodynamic Modeling for Selected Binary and Ternary Systems of Light Paraffins and Aluminum Alkyls written by Allen Michael Beard and published by . This book was released on 1997 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamic Modeling and First principles Calculations of the Cr Hf Y Ternary System written by Bradley Hasek and published by . This book was released on 2010 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the thermodynamic modeling of the ternary Cr-Hf-Y system. Chromium, hafnium, and yttrium are all used as alloying elements in nickel superalloys. Nickel superalloys usually contain many different alloying elements, so there becomes a need to understand the phase equilibria of large, multicomponent systems. This can be accomplished by using the CALPHAD method of modeling. CALPHAD modeling requires experimental data to better model the system. In the absence of experimental data, first-principles calculations can be used to predict thermochemical data. Before modeling the Cr-Hf-Y system, the binary Cr-Hf, Cr-Y, and Hf-Y systems must be modeled. In the Cr-Y and Hf-Y system, there is limited experimental data, so first-principles calculations are done on the BCC and HCP solid solution phases using special quasirandom structures (SQS's) to model the disordered systems. The symmetry is also investigated to ensure symmetry is not lost during relaxation. Using the first-principles calculations, the enthalpy of mixing is used to model these systems. The Cr-Hf system is modeled with experimental data and with first-principles calculations done on the Laves phase. With the three binary systems modeled, the ternary system is then modeled without any experimental data present. Isothermal sections are presented from 1273 K to 2200 K.
Download or read book Thermodynamic Modeling and Experimental Investigation of the Mg Al Ca Sr System written by Mohammad Aljarrah and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, a self-consistent thermodynamic database for the Mg-Al-Ca-Sr system using the modified quasichemical model has been constructed. The thermodynamic description of the quaternary system was established by combining the thermodynamic descriptions of the constituent binary and ternary sub-systems. The Mg-Al-Ca and Mg-Al-Sr systems were investigated by combining thermodynamic modeling and experimental investigation. The experimental investigation has been performed using DSC, XRD, SEM and EPMA. Also, isothermal sections at 300°C and 400°C were constructed for the Mg-Al-Ca and Mg-Al-Sr systems. In the Mg-Al-Sr system, six ternary solubilities of the binary compounds extended into the ternary system have been found and denoted as (Mg 17 Sr 2), (Mg 23 Sr 6), (Mg 38 Sr 9), (Mg 2 Sr), (Al 4 Sr) and (Al 2 Sr). The reported ternary compound in the literature (Mg 58 Al 38 Sr 4) has been observed in this work. In the Mg-Al-Ca system, three binary compounds were found to dissolve the third component in the ternary system and were denoted as (Al 2 Ca), (Al 3 Ca 8), and (Mg 2 Ca). The ternary compound (C36) reported in the literature has been confirmed. A comparison between the calculated liquidus projection of the Mg-Ca-Sr system using the modified quasichemical model and random solution model has been presented. It was found that while the random solution model agrees well with the experimental phase diagram, the modified quasichemical model gives better agreement with the experimental thermodynamic data and the experimental phase diagram. Liquidus projection of the Al-Ca-Sr system was calculated using the modified quasichemical model and combined with the other three ternaries in one database for the Mg-Al-Ca-Sr system.
Download or read book Thermodynamic Modeling of the Mg Al Ca Zn Systems written by Sk. Wasiur Rahman and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Critical assessment of the experimental data and re-optimization of the binary Mg-Zn, Ca-Zn, Al-Zn, Al-Ca systems and the Laves phase in the Mg-Ca system have been performed. A Comprehensive thermodynamic database of the Mg-Ca-Zn and Al-Ca-Zn ternary systems is presented from the constituent binary systems using suitable extrapolation methods. All available as well as reliable experimental data both for the thermodynamic properties and phase boundaries are reproduced within experimental error limits. In the present assessment, the Modified Quasichemical Model in the pair approximation is used for the liquid phase to account for the presence of the short-range ordering properly. The intermediate solid solutions are modeled using the compound energy formalism. Since the literature included contradicting information regarding the ternary compounds in both ternary systems, thermodynamic modeling of phase equilibria is used to determine the most likely description of the two ternary systems and to exclude the self-contradicting experimental observations. The constructed database is used to calculate both the integral and partial thermodynamic properties of the constituent binary systems. Moreover, the liquidus projections, isothermal sections and vertical sections of the ternary systems are also calculated and the invariant reaction points are predicted using the constructed database.
Download or read book Thermodynamic Properties of Binary and Ternary Systems written by Timo Kaivamo and published by . This book was released on 1983 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamic Modeling and Experimental Investigation of the Mg Cu Ni Y Quaternary System written by Md. Mezbahul Islam and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamic properties of binary and ternary systems related to vapor liquid equilibria written by Pokkunuri Satyanarayana Murti and published by . This book was released on 1956 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prediction of Extensive Thermodynamic Quantities for Ternary Systems Using Binary Data written by Norman James Olson and published by . This book was released on 1964 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solubility in Supercritical Carbon Dioxide written by Ram B. Gupta and published by CRC Press. This book was released on 2006-12-06 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid extraction is an environmentally safe and cost-effective alternative to traditional organic solvents. Carbon dioxide is widely used as the solvent of choice for applications such as caffeine and nicotine extraction due to its mild critical temperature, nontoxicity, nonflammability, and low cost. Introducing the most complete col
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 702 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.
Download or read book Supercritical Fluids written by E. Kiran and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluids are neither gas nor liquid, but can be compressed gradually from low to high density and they are therefore interesting and important as tunable solvents and reaction media in the chemical process industry. By adjusting the density the properties of these fluids can be customised and manipulated for a given process - physical or chemical transformation. Separation and processing using supercritical solvents such as CO2 are currently on-line commercially in the food, essential oils and polymer industries. Many agencies and industries are considering the use of supercritical water for waste remediation. Supercritical fluid chromatography represents another, major analytical application. Significant advances have recently been made in materials processing, ranging from particle formation to the creation of porous materials. The chapters in this book provide tutorial accounts of topical areas centred around: (1) phase equilibria, thermodynamics and equations of state; (2) critical behaviour, crossover effects; (3) transport and interfacial properties; (4) molecular modelling, computer simulation; (5) reactions, spectroscopy; (6) phase separation kinetics; (7) extractions; (8) applications to polymers, pharmaceuticals, natural materials and chromatography; (9) process scale-up.
Download or read book Supercritical Fluid Science and Technology written by Keith P. Johnston and published by . This book was released on 1989 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: New directions in supercritical fluids science and technology, fluorescence spectroscopy studies of intermolecular interactions in supercritical fluids, solvation structure in supercritical fluid mixtures based on molecular distribution functions, gibbs-ensemble Monte Carlo simulations of phase equilibria in supercritical fluid mixtures, spectroscopic determination of solvent strength and structure in supercritical fluid mixtures, partition coefficients of polyethyle glycols in super critical carbon dioxide, experimental measurement of supercritical fluid-liquid phase equilibrium, vapor-liquid equilibria of fatty acid esters in supercritical fluids, four-phase equilibrium of two ternary organic systems with carbon dioxide, direct viscosity enhancement of carbon dioxide, inverse emulsion polymerization of acrylamide, interaction of polymers with near-critical carbon dioxide, fundamental kinetics of methanol oxidation in supercritical fluids, thermodynamic analysis of corrosion of iron alloys in supercritical water, electrochemical measurements of corrosion of iron alloys in supercritical water, phase and reaction equilibria considerations in the evaluation and operation of supercritical fluid reaction processes, kinetic model for supercritical delignification of wood, gas antisolvent recrystallization solids formation after the expansion of supercritical mixtures, food, pharmaceutical, and environmental applications, design of commercial plant.
Download or read book Solvent Systems and Their Selection in Pharmaceutics and Biopharmaceutics written by Patrick Augustijns and published by Springer Science & Business Media. This book was released on 2007-08-06 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solvent systems are integral to drug development and pharmaceutical technology. This single topic encompasses numerous allied subjects running the gamut from recrystallization solvents to biorelevant media. The goal of this contribution to the AAPS Biotechnology: Pharmaceutical Aspects series is to generate both a practical handbook as well as a reference allowing the reader to make effective decisions concerning the use of solvents and solvent systems. To this end, the monograph was created by inviting recognized experts from a number of fields to author relevant sections. Specifically, 15 chapters have been designed covering the theoretical background of solubility, the effect of ionic equilibria and pH on solubilization, the use of solvents to effect drug substance crystallization and polymorph selection, the use of solvent systems in high throughput screening and early discovery, solvent use in preformulation, the use of solvents in bio-relevant dissolution and permeation experiments, solvents and their use as toxicology vehicles, solubilizing media and excipients in oral and parenteral formulation development, specialized vehicles for protein formulation and solvent systems for topical and pulmonary drug administration. The chapters are organized such that useful decision trees are included together with the scientific underpinning for their application. In addition, trends in the use of solvent systems and a balance of current views make this monograph useful to both the novice and experienced researcher and to scientists at all developmental stages from early discovery to late pharmaceutical operations.
Download or read book Energy Efficient Solvents for CO2 Capture by Gas Liquid Absorption written by Wojciech M. Budzianowski and published by Springer. This book was released on 2016-12-01 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews and characterises promising single-compound solvents, solvent blends and advanced solvent systems suitable for CO2 capture applications using gas-liquid absorption. Focusing on energy efficient solvents with minimal adverse environmental impact, the contributions included analyse the major technological advantages, as well as research and development challenges of promising solvents and solvent systems in various sustainable CO2 capture applications. It provides a valuable source of information for undergraduate and postgraduate students, as well as for chemical engineers and energy specialists.
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
