An Overview of the Drug Discovery and Development

It should be noted that the descriptions in this book on discovery and regulatory processes are mainly for ethical drugs, as opposed to over-the-counter (OTC) drugs. Ethical drugs are prescription drugs that require prescriptions by physicians, whereas OTC drugs can be purchased from 

There is a further differentiation of ethical drugs into new drugs (those covered by patents) and generics (copies of drugs that have expired patents). Most of the descriptions in this book apply to new drugs. 

Although human civilization has been experimenting and consuming drugs for many centuries, it is only in the past 100 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 the ancient times. 

Discovery targets receptors, small molecule drugs, large molecule drugs 

Development Methodologies following GLP-pharmacodynamics, pharmacokinetics, toxicology, drug delivery systems 

---

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.)... 

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. 

An overview of the role of the virus-associated glycoprotein sialidase (neuraminidase) and some of the most recent developments towards the discovery of anti-influenza drugs based on the inhibition of influenza virus sialidase is provided in this chapter. 

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... 

In this chapter we have given an overview of the two major approaches used in NMR and drug discovery, structure-based design and NMR-based screening. Both areas are flourishing and, together with more traditional uses of NMR, they demonstrate the versatility of NMR as a tool in medicinal chemistry. The power of NMR has been dramatically enhanced over the last decade by developments... 

The aim of this section is to cover approaches to assay selection, to provide an overview of the possible assay formats and to give a description of the most frequently used assay formats for potency determinations. Bioassays are developed and used for different purposes during drug discovery and development. Even though they can have the same assay format they have a different purpose in a product development cycle starting from target selection to clinical biomarkers. 

---