Download or read book Thermodynamics of Lipid Based Drug Delivery Systems written by Joscha Brinkmann and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lipid Based Drug Delivery Systems written by Bhupendra Prajapati and published by CRC Press. This book was released on 2023-12-01 with total page 837 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book appraises the role of lipid-based drug delivery systems (LBDDSs) with respect to the bioavailability and controlled delivery of complex drug molecules for improving their clinical viability. It covers the latest developments and advancements in the field of drug delivery, and explores and compiles information on the current situation of lipid-based formulations used as versatile excipients and all their possible routes to improve therapeutic benefits. The book discusses novel formulations such as depot formulations, micro- and nanoemulsions, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), liposomes, nanoliposomes, micelles, nanosuspensions, lipid implants and inserts, and lipid nanotubes. It presents preparation methods of LBDDSs and their physicochemical properties, and portrays their various application angles and their impacts on drug-conveyance frameworks when employed in vitro and in vivo. The book is beneficial for researchers working on lipid-based drug formulations as well as biological and translational drug delivery. It is also a useful resource for course work of students of various academic degree programs such as pharmacy, health sciences, biotechnology, and microbiology; postgraduate and PhD students; and postdoctoral fellows researching on nanomedicine-based drug delivery systems.
Download or read book Oral Lipid Based Formulations written by David J. Hauss and published by CRC Press. This book was released on 2007-06-08 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oral lipid-based formulations are attracting considerable attention due to their capacity to facilitate gastrointestinal absorption and reduce or eliminate the effect of food on the absorption of poorly water-soluble, lipophilic drugs. Despite the obvious and demonstrated utility of these formulations for addressing a persistent and growing problem
Download or read book Understanding the Determinants of Drug Absorption Following Oral Administration of Lipid based Drug Delivery Systems written by Mette Uhre Anby and published by . This book was released on 2012 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current project has explored the determinants of drug absorption following oral administration of lipid-based drug delivery systems (LBDDS) and the role of intestinal digestive processes on formulation performance. Particular focus has been directed to the role of formulation excipients and drug loading on the generation and maintenance of drug supersaturation during LBDDS processing and the subsequent impact on drug bioavailability. The data show that initiation of digestion by pancreatic enzymes functions as an effective supersaturation trigger and that addition of polymeric precipitation inhibitors (PPI) may be utilised to stabilise supersaturation for longer periods and therefore to enhance absorption. Formulation performance was highly correlated with the maximum degree of supersaturation that the formulation generated on dispersion and digestion. In vitro, increasing drug dose initially increased drug thermodynamic activity in the aqueous colloidal phases formed by formulation digestion. Above a critical drug loading, however, supersaturation 'pressure' increased to a point above which nucleation and crystal growth dominated, resulting in drug precipitation. The utilisation of lower drug loads, higher surfactant levels, reduced cosolvent and the addition of PPI all enhanced formulation performance in vitro (i.e. supported ongoing solubilisation), however, subsequent studies showed that only in some cases was the addition of PPI able to support enhanced absorption in vivo. Consistent with the potential for increases in thermodynamic activity with increase in drug dose, non-linear increases in bioavailability were evident after administration of a series of LBDDS containing increasing quantities of drug to beagle dogs. In further alignment with the in vitro data, non-linear increases in bioavailability were also only evident up to a critical point, beyond which further increases in drug dose resulted in a reduction in bioavailability. The initial in vivo studies were therefore highly consistent with the in vitro supersaturation data. Replication of the in vivo study in a younger cohort of animals, however, was not able to reproduce the same trends and linear increases in exposure with dose were apparent in this animal cohort. Further studies failed to show a significant difference in hepatic function across the two cohorts, and instead suggested that age-related changes in GI solubilisation, potentially through increased bile salt secretion in the older cohort, may have led to better stabilisation of supersaturation and therefore increases in danazol absorption. Increases in the quantity of drug absorbed at higher doses in the older cohort may have also magnified differences in exposure due to greater saturation of first pass metabolism. The latter data led to a more detailed evaluation of the role of drug dose on the bioavailability of danazol from LBDDS. These studies were conducted in rats to allow more direct exploration of the role of first pass metabolism, and gastric and intestinal processing on danazol bioavailability. Surprisingly, danazol exposure in the rat following oral administration of danazol formulated in similar LBDDS as those used in the dog studies was low ( 12%), and incorporation of PPI had limited effect. In contrast, co-administration of an inhibitor of CYP450 enzymes resulted in a large increase in bioavailability suggesting that the major limitation to oral bioavailability was first pass metabolism. The applicability of previous in vitro models of lipid digestion to events in the rat was also examined, and a number of modifications to the model suggested. The data obtained indicate that in the rat, lipid digestion may be less efficient than it is in the dog (or human), and therefore that digestion-mediated reductions in solubilisation capacity are less important, that danazol absorption from LBDDS formulations is high ( 50%) and that the principle limitation to danazol bioavailability in the rat is first pass metabolism. In summary, this thesis contributes to a better understanding of the mechanisms by which LBDDS promote drug solubilisation and absorption and specifically to the influence of drug dose, animal model and the inclusion of polymeric precipitation inhibitors (PPI) on supersaturation generation and stabilisation.
Download or read book Lipid Based Drug Delivery Systems for Parenteral Delivery of Proteins written by Lene Jørgensen and published by . This book was released on 2004 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding Drug Release and Absorption Mechanisms written by Mario Grassi and published by CRC Press. This book was released on 2006-12-26 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demand for better reliability from drug delivery systems has caused designers and researchers to move away from trial-and-error approaches and toward model-based methods of product development. Developing such models requires cross-disciplinary physical, mathematical, and physiological knowledge. Combining these areas under a single cover, Under
Download or read book Understanding Drug Release and Absorption Mechanisms written by and published by CRC Press. This book was released on 2007 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demand for better reliability from drug delivery systems has caused designers and researchers to move away from trial-and-error approaches and toward model-based methods of product development. Developing such models requires cross-disciplinary physical, mathematical, and physiological knowledge. Combining these areas under a single cover, Understanding Drug Release and Absorption Mechanisms builds a firm understanding ofall elements needed to conceive, build, and implement successful models of drug release. Written by experts with broad industrial and academic experience, this book discusses the underlying physical principles, shows how to build mathematical models based on these principles, and finally compares the resulting models with experimental results. The authors begin by introducing the basics of modeling, physiological details of gastrointestinal and dermal absorption pathways, rheology, mass transport and thermodynamics, dissolution and partitioning, as well as size effects on the dissolution of crystallites. From this baseline, the authors explore applications in drug release from various delivery systems, specifically matrix systems, microemulsions, and permeability through membranes. Working systematically from theory to working models, Understanding Drug Release and Absorption Mechanisms: A Physical and Mathematical Approach demonstrates the steps involved in designing, building, and implementing realistic and reliable models of drug release without unrealistically simplifying the theoretical parameters.
Download or read book Strategies for Exploiting the Full Potential of Oral Lipid based Drug Delivery Systems written by Gattefossé and published by . This book was released on 2007 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioinspired Symmetrical Lipids for Controlled Drug Delivery written by Sara Yazdi and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designing new drug delivery systems requires tight control of drug release kinetics. Historically, polymers have been strong contenders in the field. However, achieving a narrow polydispersity and reducing batch-to-batch variability in synthesis can be difficult. Therefore researchers have expanded to other materials such as lipids, which mat have more favorable drug release properties. Lipids are a chemically unique category of molecules that plays a role in functionality and architecture of all living cells. Thus when used as materials for design of drug delivery systems, they will be considered biodegradable and biocompatible. In addition they offer more robust control over design of molecular architecture and thus directly impact the release kinetics of model drugs. The aim of this study was to better understand the mass transport mechanism involved in controlled release of a model drug from lipid based parenteral delivery systems. A family of dihydroxyacetone (DHA) derived symmetrical lipids with varying hydrocarbon chain length was synthesized to systematically analyze how lipid chain length influences drug release kinetics. Our results showed that microparticles prepared using solvent emulsification are porous and polydisperse in size. The effects of several formulation and processing parameters (lipid and surfactant concentration) on the resulting release kinetics were measured. As expected smaller particles (25[MICRO SIGN]m) showed faster release kinetics possibly due to shorter diffusion pathway length compared to the larger particles ([25-40] [MICRO SIGN]m and 40 [MICRO SIGN]m). Our results showed that porosity controls the release kinetics of the anti-inflammatory drug piroxicam more strongly than hydrophobicity. Further investigation of parenteral delivery systems made from DHA derived symmetrical diglcycerides showed that protein release is dependent on the hydrophobicity of the matrix. With lysozyme as a model protein drug, long chain diglycerides (C16 and C14) showed slower release compared to short chain, less hydrophobic diglycerides (C10 and C12). As with solid microparticles, the effect of varying formulation and processing parameters (e.g. lysozomal loading, compression force) was studied. SDS gel electrophoresis and enzymatic study in M. lysodeikticus suspensions were used to study the structural integrity and activity of dispersed model drug. The results showed that there is slight aggregation and loss of activity possibly as a result of heat generation during compression. Furthermore diglyceride implants showed acute inflammatory response in early time points of the biocompatibility study conducted using rat animal models. The inflammatory response subsided for later time points. Histological inspection of the tissues showed presence of granulomas but no sign of tissue necrosis.
Download or read book Lipid based Drug Delivery System written by Mohan Babu Boggara and published by . This book was released on 2009 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Outlook for Novel Lipid based Drug Delivery Systems written by Dan Lasic and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation and Optimization of a Lipid Based Drug Delivery System with Enhanced Dissolution Solubility Properties written by Mahmoud Mohammad Jaber Thawabtah and published by . This book was released on 2006 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Dynamics Simulations of Lipid based Drug Delivery Systems written by Woldeamanuel Anteneh Birru and published by . This book was released on 2015 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular dynamics (MD) simulation is a powerful technique to investigate molecular self-assembly. It can be used to model and understand the interactions of biological membranes, proteins, and lipids. Above their critical micelle concentration (CMC), molecules that are composed of hydrophilic head group and hydrophobic tail group aggregate spontaneously to form a wide variety of assemblies ranging from micelles, rodlike structures, and bilayers to more complex phases such as hexagonal and cubic phases. These self-assembly processes are of fundamental importance in drug discovery and development. In the area of drug discovery and development, it is vital to have an effective means of improving the bioavailability of poorly water-soluble drugs (PWSD). Lipid-based delivery systems (LBDDS) are one of the important approaches of improving the bioavailability of PWSD. The nature of gastrointestinal (GI) fluids strongly influences the absorption of PWSDs. The dissolution rate and the amount of drugs dissolved is determined by the nature of the GI fluids and their solubilisation capacity. Within the GI tract there are endogenous as well as exogenous solubilising components. The endogenous components are secreted from the gall bladder, whereas the exogenous components are those which are administered in the drug formulation as well as resulting from meals. After oral administration, drugs must remain dissolved within the GI tract before partitioning into and then across the enterocyte. Although the self-assembly process of lipids and lipophilic excipients within the GI tract are thought to have a significant influence on drug solubilisation and the degree of drug supersaturation, the molecular understanding of these structures is limited. The first section of this work describes the modification of the GROMOS 53A6 united atom force field particularly for polyethylene glycol (PEG). Then, using MD simulations and experimental methods such as turbidity, particle size measurement, cross-polarized light microscopy and NMR, the current study explores the phase behaviour of (i) the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), sodium glycochenodeoxycholate (GDX), and water system, and (ii) the 1-palmitoyl-2-hydroxy-sn-glycerol-3-phosphocoline (Lyso PC), GDX and water system and constructs ternary phase diagrams of these mixtures. It also investigates part of the quaternary phase diagram of Lyso PC, glycerol 1-monooleate (GMO), GDX and water, which was used to investigate the structures formed in the intestine after digestion of triglycerides. The solubilisation capacity of the lipidic microenvironment on PWSD has also been investigated using LC-MS and MD simulation. The association structures of these various systems have been modelled and compared to the experimental phase behaviour of the analogous systems. It is indicated in these studies that digestion and digested products have a significant impact on the phase behaviour of the contents of the small intestine and on solubilisation and bioavailability of PWSDs. In summary, this thesis contributes to a better understanding of the performance of lipid-based formulations (LBF) and shines a light on the use of MD simulations as a prediction tool to model LBDDS.
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
Download or read book Degradation of Lipid Based Drug Delivery Systems and Characterization of Semi synthetic Spider Silk Proteins for the Application in Pharmaceutical Technology written by Martin Schwab and published by . This book was released on 2009 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamics and Biophysics of Biomedical Nanosystems written by Costas Demetzos and published by Springer. This book was released on 2019-03-04 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the recent advances of thermodynamics and biophysics in drug delivery nanosystems and in biomedical nanodevices. The up-to-date book provides an in-depth knowledge of bio-inspired nanotechnological systems for pharmaceutical applications. Biophysics and thermodynamics, supported by mathematics, are the locomotive by which the drug transportation and the targeting processes will be achieved under the light of the modern pharmacotherapy. They are considered as scientific tools that promote the understanding of physicochemical and thermotropic functionality and behavior of artificial cell membranes and structures like nanoparticulate systems. Therefore, this book focusses on new aspects of biophysics and thermodynamics as important elements for evaluating biomedical nanosystems, and it correlates their physicochemical, biophysical and thermodynamical behaviour with those of a living organism. In 2018, Prof. Demetzos was honored with an award by the Order of Sciences of the Academy of Athens for his scientific contribution in Pharmaceutical Nanotechnology.
Download or read book Oral Drug Absorption written by Jennifer B. Dressman and published by CRC Press. This book was released on 2016-04-19 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oral Drug Absorption, Second Edition thoroughly examines the special equipment and methods used to test whether drugs are released adequately when administered orally. The contributors discuss methods for accurately establishing and validating in vitro/in vivo correlations for both MR and IR formulations, as well as alternative approaches for MR an
