Controlled Release Of Pesticides And Pharmaceuticals

First Published in 1985, this book offers comprehensive insight into the process of administering chemical ingredients. Carefully compiled and filled with a vast repertoire of notes, diagrams, and references this book serves as a useful reference for students of pharmacology and other practitioners in their respective fields.

Since the middle of the Sixties, new types of formulation for biologically active com pounds have been developed, which have been introduced into the literature under the term Controlled Release Formulations (CRF). Stimulated by results from former and successful pharmaceutical research, which was engaged in the production of prepa rations with protracted effects (introduction onto the market in the year 1952 of D amphetamine in the form of pellets, coated to varying degrees with fats and waxes) 1), experiments were carried out to transfer the prolongation of effectiveness to pesticidal substances also, by means of a depot formulation. Initial work was concerned with the production of protective coatings for sonar systems in marine ecosystems. By means of antifouling paints or rubber coatings containing tri-n-butyl-tin oxide (TBTO), the growth of marine organisms on sonar domes, buoys and hulls in the water could be effectively prevented 2. 3). Controlled release formUlations of pesticides are defined as depot systems which continuously release their toxic constituents into the environment over a specified period of time (usually months to years) 4). According to this definition, such formu lations can be successfully employed where a chronic exposure to biologically active compounds is required over a longer period. The following hypothetical example is intended to illustrate this 5). In Fig. 1, the duration of activity of a non-persistent pesticide with a loss rate under environmental conditions of t1/2 = 15 days, is graphically illustrated.

Controlled Release of Bioactive Materials is a collection papers that deal with the study of controlled release applications in drugs and other pharmacological products and processes. The text covers topics such as the theory and practice of controlled drug delivery from bioerodible polymers, biodegradable drug delivery systems from aliphatic polyesters, and the applications of osmotic drug delivery. Also covered are topics such as the application of polymers for the sustained release of macromolecules, controlled transdermal delivery, and the use of hydrogel devices for the controlled release of steroid hormones. The book is recommended for pharmacologists and doctors who would like to know more about advancements in the field of controlled release applications and its uses in healthcare, especially in pharmacology.

Controlled release technology enhances the beneficial effects of drugs, agrochemicals, and other biologically active agents. This monograph offers background on the terms, concepts, mathematical and chemical principles, and the advantages of, controlled release technology. Treats each of the major techniques of achieving controlled release: diffusion, biodegradation, osmosis, and mechanical systems. Describes and compares the numerous materials used in controlled release devices. Presents techniques for device preparation and evaluation. Describes the most significant commercially available controlled release products.

The concept of controlled release has attracted increasing attention over the last two decades, with the applications of this technology proliferating in diverse fields in cluding medicine, agriculture and biotechnology. Research and developmental efforts related to controlled release are multiplying in both industry and academia. The reason for this phenomenal growth is obvious. The use of a variety of biologically active agents, such as drugs, fertilizers and pesticides, has become an integral part of modern society. Along with the use of these reagents has evolved an awareness that their uncontrolled application almost inevitably induces harmful effects on the health of humans and their surrounding environments. To eliminate or minimize these harmful effects necessitates the controlled release of these chemicals. Moreover, the controlled release of substances, not usually considered toxic or hazardous, e.g., some catalysts and nutrients, can enhance their effectiveness. The number and variety of controlled release systems, differing in their physical and chemical makeup, are increasing rapidly. Proliferation almost always demands correlation, generalization and unification; it requires both the development of underlying theories of their behavior and the mechanistic interpretation of their performance. This, in turn, requires a statistical and mathematical (quantitative) treatment of the scientific information and technical data pertaining to them. A quantitative treatment can also facilitate the formulation of procedures for computer-aided design of these systems through a priori prediction of their per formance for a variety of design parameters.