Controlled Release Of Biologically Active Agents

The Symposium on Controlled Release of Biologically Active Agents was held under sponsorship of Southern Research Institute in Birmingham, Alabama, April 19 and 20, 1973. The announced purpose of the symposium was to encourage an exchange of information among the ex perts working in various fields of controlled release and the scientists and technologists interested in applying the concepts. The number of registrants (over 120), the diverse nature of the organizations represented, and the enthusiastic participation of attendees in the discussions testified to intense and broad interests in controlled release. The papers pre sented at the symposium should serve well to introduce the principles of controlled release and demonstrate a few of the promising applications. Controlled release is an important step toward im proving the delivery of a biologically active agent to its target. Precise administration of an agent can substantially reduce the concentration required for beneficial effects and thus minimize deleterious effects to the organism or to the environment. Through con trolled release, older agents whose efficacies are established may prove more reliable, and newer agents whose high potencies or low stabilities have inhibited use may prove more suitable. Controlled release there fore offers both an alternative and a complementary route to the increasingly costly and demanding search for agents of greater specificity.

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.

The Handbook of Pharmaceutical Controlled Release Technology reviews the design, fabrication, methodology, administration, and classifications of various drug delivery systems, including matrices, and membrane controlled reservoir, bioerodible, and pendant chain systems. Contains cutting-edge research on the controlled delivery of biomolecules! Discussing the advantages and limitations of controlled release systems, the Handbook of Pharmaceutical Controlled Release Technology covers oral, transdermal, parenteral, and implantable delivery of drugs discusses modification methods to achieve desired release kinetics highlights constraints of system design for practical clinical application analyzes diffusion equations and mathematical modeling considers environmental acceptance and tissue compatibility of biopolymeric systems for biologically active agents evaluates polymers as drug delivery carriers describes peptide, protein, micro-, and nanoparticulate release systems examines the cost, comfort, disease control, side effects, and patient compliance of numerous delivery systems and devices and more!

The development of improved methods of drug delivery has received significant attention over the last two decades. Most important is a non-toxic level of the drug at a particular body organ or body locale. To reach this goal, many variations of controlled release have been researched worldwide. This edited volume of papers from the Journal of Biomaterials Applications details many exciting technical advances in controlled release drug delivery systems. Some of the important developments described in the book include implantable delivery systems, delivery of topical drugs, and ultrasonic drug delivery.