An Overview of the Drug Discovery and Development Process

Although human civilization has been experimenting and consuming drugs for many centuries, it is only in the past hundred years that the foundation was laid for the systematic research and development of drugs. Readers are referred to Appendix 1 for a brief description of the history of drug development since ancient times. 

personnel from a myriad of fields are involved in the process of drug discovery and development, from scientists, clinicians, and medical practitioners to statisticians. Even persons from seemingly disparate occupations, such 

It is estimated that, on average, a drug takes 10-12 years from initial research to reach the commercialization stage. The cost of this process is estimated to be more than US 1 billion. From discovery to marketing approval of a drug, the stages involved are shown in Fig. 1.1. 

Drug Development Tests are performed on the lead compounds in test tubes (laboratory, in vitro) and on animals (in vivo) to check how they affect the biological systems. The tests, often called preclinical research activities. 

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This chapter aims to provide chemists and biotechnologists with an overview of the state of biocatalysis and its application to different reactions in the drug discovery and development process. In Section 16.2, biocatalysts that catalyze different chemical reactions will be introduced. In Section 16.3, selected examples of mulhstep enzymatic reactions will be highlighted. Finally the chapter will be wrapped up with a discussion on current trends and future perspectives. 

The first edition1 of this book was published approximately 13 years ago. Its primary objective was to present an overview and a "roadmap" of the process of new drug discovery and development, particularly oriented to individuals or companies entering the pharmaceutical field. It was written by one of the authors (Smith), with no contributors, and drawn on Smith s experiences in the industry and field over the course of nearly 40 years. In the second edition, the scope of the first book has been expanded and technical details in the form of hard data have been included. In addition to the editors own commentary and contributions, the major part of the book is the result of contributions of experts in the industry. New chapters on risk assessment, international harmonization of drug development and regulation, dietary supplements, patent law, and entrepreneurial startup of a new pharmaceutical company have been added. Some of the important, basic operational aspects of drug discovery and development (e.g., organizational matters, staff requirements, pilot plant operations, etc.) are not repeated in this book but can be found in the first edition. 

FIGURE 2.3 An overview of the drug development process that illustrates the activities within the four major stages of drug development drug discovery, preclinical development, clinical development, and manufacturing. (Courtesy of Milestone Development Services, Newtown, PA, 1998. With permission.)... 

To give an overview of the breadth of applications of NMR, Fig. 12.1 summarizes the drug development process and indicates the role of NMR at various stages. Drug development is an iterative process and can be simplified by representing it with two interconnected cycles of activity. Cycle A involves the design or discovery of an initial lead followed by its synthesis and bioassay. Based on the initial assay results there may be several loops around this... 

This chapter will review some of the important methods for carrying out in vivo absorption and bioavailability studies, as well as attempt to provide an overview of how the information may be used in the drug discovery process. The chapter is aimed at medicinal chemists and thus will focus on the use of animals in discovery phase absorption, distribution, metabolism, and excretion/pharmacokinetic (ADME/PK) studies, rather than the design of studies that are for regulatory submission, or part of a development safety package. 

With more than 180 illustrations and an eight-page color insert, this valuable reference explores multiple modern mass spectrometry techniques and strategies. It includes an excellent overview of the entire drug discovery process plus the latest developments on how mass spectrometry is used to support this endeavor. 

In Chapter 2, Ganesan gives a historical overview of the development of natural products research and shows the importance of combinatorial chemistry approaches to such compounds in the drug discovery process. Examples from his research help to illustrate the value and future of such an integrated approach to drug discovery using natural-product-like libraries. 

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