This book comprehensively reviews drug stability and chemical kinetics: how external factors can influence the stability of drugs, and the reaction rates that trigger these effects. Explaining the important theoretical concepts of drug stability and chemical kinetics, and providing numerous examples in the form of illustrations, tables and calculations, the book helps readers gain a better understanding of the rates of reactions, order of reactions, types of degradation and how to prevent it, as well as types of stability studies. It also offers insights into the importance of the rate at which the drug is degraded and/or decomposed under various external and internal conditions, including temperature, pH, humidity and light. This book is intended for researchers, PhD students and scientists working in the field of pharmacy, pharmacology, pharmaceutical chemistry, medicinal chemistry and biopharmaceutics.

This book is an edited version of lectures given by the authors at a seminar at the Rand Afrikaans University. It gives a survey on the Painlev‚ test, Painlev‚ property and integrability. Both ordinary differential equations and partial differential equations are considered.

Chemical Kinetics and Reaction Dynamics brings together the major facts and theories relating to the rates with which chemical reactions occur from both the macroscopic and microscopic point of view. This book helps the reader achieve a thorough understanding of the principles of chemical kinetics and includes: Detailed stereochemical discussions of reaction steps Classical theory based calculations of state-to-state rate constants A collection of matters on kinetics of various special reactions such as micellar catalysis, phase transfer catalysis, inhibition processes, oscillatory reactions, solid-state reactions, and polymerization reactions at a single source. The growth of the chemical industry greatly depends on the application of chemical kinetics, catalysts and catalytic processes. This volume is therefore an invaluable resource for all academics, industrial researchers and students interested in kinetics, molecular reaction dynamics, and the mechanisms of chemical reactions.

Chemical kinetics aims to explain the factors governing the change with time of chemical systems. The results enable one to define optimum technico-economic condi tions (such as the choice of batch or continuous processes; of concentration, temperature, and pressure; of whether to use a catalyst) for the preparation of products, so that kinetics is intimately bound up with many processes of chemical industry (production, explosions, combustion, propulsion in air and in space). On another level, kinetic studies are indispensable for understanding reaction mechanisms, which implies a de tailed knowledge of the different chemical intermediates (possibly very transitory) of a chemical reaction. But in practice it is rarely possible to work with microscopic quantities of reagents and, with the exception of crossed molecular beams, all methods give only statistical results concerning a large number of molecules. Because of this restriction, it has not always been possible to establish conclusively a reaction mechanism, even for reactions ap parently simple. Numerous attempts have been made to calculate rate constants from the physical properties of the participating molecules; but the introduction of the 'time' factor into calculations of the distribution of energies of chemical processes makes this very difficult, so that the elucidation of mechanisms still depends almost entirely on experi mental studies. However, several theories have been elab orated which, in giving a more and more precise picture of the reaction process, have proved very fruitful, and have become indispensable in designing experiments.

Processes involving randomly moving particles, which react either upon encounter or via distance-dependent reaction rates, are ubiquitous in nature. A few stray examples are recombination of ions or holes and electrons, excitation energy migration and quenching, trapping of particles by other species, coagulation, binding of ligands and proteins to specific sites, chemotaxis, catalytically-induced self-propulsion, polymerization, growth of dendrites or aggregates, or nuclei of a new phase.Several decades ago, it was recognized that the kinetic behavior in some systems with reactions and random transport is strongly affected by many factors, which were not taken into account in previous studies. These are, to name but a few, fluctuations in the spatial distributions of the reactants and fluctuations of the reactivity, some essentially many-particle phenomena, effects of anomalous diffusion, molecular crowding, as well as the internal geometry of the reaction bath. Within recent years, along with a growing interest in chemical processes ocurring in biological systems or cellular environments, numerous advances have been made and considerable knowledge has been acquired. These seminal contributions are, however, scattered among many journals and no attempt has been made so far to present a unified picture.This book presents a general overview of different contemporary facets of chemical kinetics in a variety of different environments. It includes 23 seminal works and reviews on different aspects of reaction processes in chemical, physical and biophysical systems, both theoretical and experimental.

The proceedings of the First Multidisciplinary International Symposium on Positive Systems Theory and Applications (POSTA 2003) held in Rome, Italy, August 28-30, 2003. Positive Systems are systems in which the relevant variables assume nonnegative values. These systems are quite common in applications where variables represent positive quantities such as populations, goods, money, time, data packets flowing in a network, densities of chemical species, probabilities, etc. The aim of the symposium was to join together researchers working in the different areas related to positive systems such as telecommunications, economy, biomedicine, chemistry and physics in order to provide a multidisciplinary forum where they have the opportunity to exchange ideas and compare results in a unifying framework.