Hot Melt Extrusion

Hot-melt extrusion (HME) - melting a substance and forcing it through an orifice under controlled conditions to form a new material - is an emerging processing technology in the pharmaceutical industry for the preparation of various dosage forms and drug delivery systems, for example granules and sustained release tablets. Hot-Melt Extrusion: Pharmaceutical Applications covers the main instrumentation, operation principles and theoretical background of HME. It then focuses on HME drug delivery systems, dosage forms and clinical studies (including pharmacokinetics and bioavailability) of HME products. Finally, the book includes some recent and novel HME applications, scale -up considerations and regulatory issues. Topics covered include: principles and die design of single screw extrusion twin screw extrusion techniques and practices in the laboratory and on production scale HME developments for the pharmaceutical industry solubility parameters for prediction of drug/polymer miscibility in HME formulations the influence of plasticizers in HME applications of polymethacrylate polymers in HME HME of ethylcellulose, hypromellose, and polyethylene oxide bioadhesion properties of polymeric films produced by HME taste masking using HME clinical studies, bioavailability and pharmacokinetics of HME products injection moulding and HME processing for pharmaceutical materials laminar dispersive & distributive mixing with dissolution and applications to HME technological considerations related to scale-up of HME processes devices and implant systems by HME an FDA perspective on HME product and process understanding improved process understanding and control of an HME process with near-infrared spectroscopy Hot-Melt Extrusion: Pharmaceutical Applications is an essential multidisciplinary guide to the emerging pharmaceutical uses of this processing technology for researchers in academia and industry working in drug formulation and delivery, pharmaceutical engineering and processing, and polymers and materials science. This is the first book from our brand new series Advances in Pharmaceutical Technology. Find out more about the series here.

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.

Over the past few decades, hot-melt extrusion (HME) techniques have been shown to exhibit remarkable potential for the manufacture of various pharmaceutical products. HME is an emerging processing technology used primarily for the manufacture of pharmaceutical solid dispersions, combining the advantages of a solvent-free process with fewer production steps making it suitable for easy to scale-up and continuous manufacturing applications. A single unit HME based operation, employing heat and mechanical shear, has displayed a significant potential to retain the stability even of thermo-labile therapeutics e.g., proteins. HME has now explicitly been established from a quality-by-design viewpoint for in-line data monitoring as per the recent guidelines issued by the US Food and Drugs Administration (FDA).This book will focus primarily on the foregoing subject areas and will be of significant interest to a broad/interdisciplinary readership across the industries and academia for, (but not limited to) the following reasons:- Emerging HME processes and applications for multiple drug delivery.- Solid-state engineering, solubility enhancement, controlled release, taste masking and sustained release case studies from a continuous manufacturing view-point.- Means to explore the potential of continuous manufacture of co-crystals for promoting solvent free production methods.- Scale-up case study and issue considerations and studies on the regulatory guidelines (FDA) for continuous manufacturing involving emerging HME techniques.

Hot-melt extrusion with poorly soluble drugs is a challenging method to enhance the solubility. The formation of solid dispersions, specifically of glassy solid solutions, wherein the drug is dispersed on a molecular basis in an inert carrier, leads to metastable systems that have advantageous dissolution behaviour but suffer from physical stability problems. To date, there is poor understanding of the solid state structure, the mechanism by which dissolution enhancement occurs, the stability on storage and in dissolution, and the processing to solid dosage forms. The hot-melt extrusion process is influenced by several parameters. The right coordination of these parameters is decisive for the production of solid dispersions and thus, the success in solubility enhancement. The solid state and the viscosity of the extrudates can be controlled by the temperature of the barrels. Besides the configuration of the screw and the temperature profile of the barrel, the design of the die plate represents the third important extrusion parameter. By keeping the dead storage capacity at a minimum, an early solidification and thus a blockage of the dies can be prevented. Due to shear forces evolving in the extruder barrel and the ability of the drug to dissolve in the molten carrier before reaching the melting temperature, the process temperature can be kept below the melting point of the substances. Basic butylated methacrylate copolymer is a suitable carrier to enhance the solubility of the poorly water-soluble drug celecoxib in a hot-melt extrusion process. The best solubility enhancement can be obtained by dispersing the drug in the molten carrier on a molecular basis and thus, to form glassy solid solutions. The solid state characteristics of the solid dispersion can be revealed by DSC analysis and interpretation of the corresponding glass transitions. Such systems may contain a drug load of up to 60% and are stable at increased temperature and humidity which is due to the very low water uptake of the components. Glassy solid solutions of celecoxib and basic butylated methacrylate copolymer have a fast dissolution rate and result in a 58 fold supersaturated solution. The mechanism of drug release from these glassy solid solutions is carrier-controlled and governed by dissolution. The enhancement of the dissolution rate is based on improved solubility and wettability. Basic butylated methacrylate copolymer interacts chemically with celecoxib in an acid-base reaction. The hot-melt extrusion process is highly dependent on the physicochemical properties of the compounds and their miscibility in the molten state. The use of basic butylated methacrylate copolymer as solubility enhancing carrier in hot-melt extrusion cannot be transferred easily to all drugs. Depending on the properties of the drug, specifically the melting point and the pKa, basic butylated methacrylate copolymer can be a useful carrier in glassy solid solution formation, but might be insufficient for solubility improvement. The formation of a glassy solid solution evolves from interactions between the drug and the carrier. Bonds can differ in their strength and can be advantageous or disadvantageous for a fast dissolution. Furthermore, decomposition processes can occur, when processing the drug at high temperatures. Thus, each formulation has to be analyzed separately. The interpretation of the chemical structure, the calculation of solubility parameters, the determination of melting temperatures and enthalpies, and the performance of molecular dynamics simulations are tools to predict the miscibility of drugs and carriers for the formulation of solid dispersions. A combined approach of tools predicting miscibility is highly appropriate, as no single technique may yield all the required information. Nevertheless, the evaluation of the melting behaviour via DSC has the highest impact. Hot-melt extruded glassy solid solutions can be processed into solid dosage forms. The mechanical energy input through milling and zabletting has no influence on the solid-state stability. The solution-state stability can be achieved by adding HPMC to the external phase. The filling of capsules with milled hot-melt extrudates is a promising technique to obtain solid dosage forms from glassy solid solutions. By the extensive analysis of the hot-melt extrusion process, the interactions of the compounds, the thermal characteristics, and the dissolution mechanism of the resulting systems, it is possible to predict the extrusion process in an early stage of development and to improve the dissolution of poorly soluble drugs.

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.

Advances and Challenges in Pharmaceutical Technology: Materials, Process Development and Drug Delivery Strategies examines recent advancements in pharmaceutical technology. The book discusses common formulation strategies, including the use of tools for statistical formulation optimization, Quality by design (QbD), process analytical technology, and the uses of various pharmaceutical biomaterials, including natural polymers, synthetic polymers, modified natural polymers, bioceramics, and other bioinorganics. In addition, the book covers rapid advancements in the field by providing a thorough understanding of pharmaceutical processes, formulation developments, explorations, and exploitation of various pharmaceutical biomaterials to formulate pharmaceutical dosage forms. Provides extensive information and analysis on recent advancements in the field of pharmaceutical technology Includes contributions from global leaders and experts in academia, industry and regulatory agencies Uses high quality illustrations, flow charts and tables to explain concepts and text to readers, along with practical examples and research case studies

The first edition of Pharmaceutical Extrusion Technology, published in 2003, was deemed the seminal book on pharmaceutical extrusion. Now it is expanded and improved, just like the usage of extrusion has expanded, improved and evolved into an accepted manufacturing technology to continuously mix active pharmaceutical ingredients with excipients for a myriad of traditional and novel dosage forms. Pharmaceutical Extrusion Technology, Second Edition reflects how this has spawned numerous research activities, in addition to hardware and process advancements. It offers new authors, expanded chapters and contains all the extrusion related technical information necessary for the development, manufacturing, and marketing of pharmaceutical dosage forms. Key Features: Reviews how extrusion has become an accepted technology to continuously mix active pharmaceutical ingredients with excipients Focuses on equipment and process technology Explains various extrusion system configurations as a manufacturing methodology for a variety of dosage forms Presents new opportunities available only via extrusion and future trends Includes contributions of experts from the process and equipment fields