Найти книгу: "Drug Bioavailability"

The peroral application (swallowing) of a medicine means that the body must first resorb the active substance before it can begin to take effect. The efficacy of drug uptake depends on the one hand on the chemical characteristics of the active substance, above all on its solubility and membrane permeability. On the other hand, it is determined by the organism's ability to absorb pharmaceuticals by way of specific transport proteins or to excrete them. Since many pharmacologically active substances are poorly suited for oral intake, a decisive criterion for the efficacy of a medicine is its so-called bioavailability. Written by an international team from academia and the pharmaceutical industry, this book covers all aspects of the oral bioavailability of medicines. The focus is placed on methods for determining the parameters relevant to bioavailability. These range from modern physicochemical techniques via biological studies in vitro and in vivo right up to computer-aided predictions. The authors specifically address possibilities for optimizing bioavailability during the early screening stage for the active substance. Its clear structure and comprehensive coverage make this book equally suitable for researchers and lecturers in industry and teaching.

Understand and assess the design, delivery, and efficacy of orally administered drugs A practical guide to understanding oral bioavailability, one of the major hurdles in drug development and delivery, Oral Bioavailability: Basic Principles, Advanced Concepts, and Applications is designed to help chemists, biologists, life science researchers, pharmaceutical scientists, pharmacologists, clinicians, and graduate and students become familiar with the fundamentals and practices of the science of oral bioavailability. The difference in rate and extent between a drug taken orally and the actual amount of a drug reaching the circulatory system, oral bioavailability is an essential parameter for determining the efficacy and adverse effects of new and developing medications, as well as finding an optimal dosing regimen. This book provides a much-needed one-stop resource to help readers better understand and appreciate the many facets and complex problems of oral bioavailability, including the basic barriers to oral bioavailability, the methods used to determine relevant parameters, and the challenges of drug delivery. In addition, this comprehensive book discusses biological and physicochemical methods for improving bioavailability, integrates physicochemistry with physiology and molecular biology, and includes several state-of-the-art technologies and approaches—Caco-2 cell culture model, MDCK, and other related cell culture models—which are used to study the science of oral bioavailability.

This book covers all aspects of bioavailability, as related to environmental contaminants. After a discussion of the definition of bioavailability and its context, focus is placed on the role of risk assessment and bioavailability. Methods of analysis are then discussed including a range of atomic spectroscopic and electrochemical techniques for metal analysis and chromatographic approaches for persistent organic pollutants (POPs). The occurrence, properties and eco-toxicity of POPs and metals in the soil/sediment environment are discussed. Particular emphasis is placed on the uptake of POPs and metals by plants (phytoextraction). Examples of POPs and metals in the environment are reviewed. Methods to assess the bioavailability of POPs and metals in the environment are discussed. The particular approaches considered are: non-exhaustive extraction techniques single extraction techniques sequential extraction techniques use of cyclodextrin and surfactants in-vitro gastrointestinal methods including physiological-based extraction test the use of bioasssays including earthworms. Finally, selected case studies highlight the importance of determining the bioavailability of POPs and metals.