Drugs

From Discovery to Approval

Rick Ng

• Publisher: Wiley-Blackwell
• Year: 2015
• ISBN:
  9781118907191
• Edition: 3
• Topic: Biological Sciences
• Subtopic: Biotechnology
• Index: Biological Sciences

The third edition of this best-selling book continues to offer a user-friendly, step-by-step introduction to all the key processes involved in bringing a drug to the market, including the performance of pre-clinical studies, the conduct of human clinical trials, regulatory controls, and even the manufacturing processes for pharmaceutical products.

Concise and easy to read, Drugs: From Discovery to Approval, Third Edition quickly introduces basic concepts, then moves on to discuss target selection and the drug discovery process for both small and large molecular drugs. The third edition incorporates the latest developments and updates in the pharmaceutical community, provides more comprehensive coverage of topics, and includes more materials and case studies suited to college and university use. Biotechnology is a dynamic field with changes across R&D, clinical trials, manufacturing and regulatory processes, and the third edition of the text provides timely updates for those in this rapidly growing field.

CHAPTER 1
INTRODUCTION

1.1 AIM OF THIS BOOK

The pharmaceutical industry is one of the most regulated industries in the world. From discovering a new drug to registering it for marketing and commercialization, pharmaceutical organizations have to negotiate through very complex and lengthy processes. These processes are necessary to ensure drug products are safe and efficacious, and that their benefits far outweigh their risks.

The intention of this book is to provide an overview of how a drug is discovered, the number and types of laboratory tests that are performed, and the conduct of clinical trials before a drug is ready to be registered for human use. Regulatory authorities play an important role in these processes, overseeing the safety and efficacy of drugs through legislation. This book aims to integrate, in a simplified manner, the relationships between all these complex processes and procedures.

To establish a frame of reference, it is necessary to commence with a definition for the term “drug”. Generally, a drug can be defined as a substance that induces a response within the human body, whether that response is beneficial or harmful. In this context, toxins and poisons can be classified as drugs. However, the term “drug” used in this book is strictly reserved for medicinal substances or pharmaceutical products, which provide favorable therapeutic or prophylactic pharmaceutical benefits to the human body. Readers are referred to Exhibit 1.1 for a definition of drug according to the Food and Drug Administration (FDA) of the United States.

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Exhibit 1.1 FDA Definition of a Drug

A drug is defined as:

• A substance recognized by an official pharmacopeia or formulary.
• A substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease.
• A substance (other than food) intended to affect the structure or any function of the body.
• A substance intended for use as a component of a medicine but not a device or a component, part or accessory of a device.
• Biological products are included within this definition and are generally covered by the same laws and regulations, but differences exist regarding their manufacturing processes (chemical process vs biological process).

Source: Data from 1. Food and Drug Administration 2012, Drugs@FDA Glossary of Terms, viewed January 6, 2014, http://www.fda.gov/drugs/informationondrugs/ucm079436.htm; 2. World Health Organization 2014, International Nonproprietary Names, viewed Jun 19, 2014, http://www.who.int/medicines/services/inn/en/

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It should be noted that there are normally three names associated with a drug: the trade or proprietary name (e.g., Lipitor), generic name, or nonproprietary name (e.g., atorvastatin), and a specific chemical name for the active ingredient (e.g., [R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid, calcium salt (2:1) trihydrate).

The International Nonproprietary Names (INN) of the World Health Organization (WHO) are the unique standard names, also known as generic names, for the active pharmaceutical ingredients in drug products.

The descriptions in this book on discovery and regulatory processes are primarily concerned with 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 pharmacies without prescriptions. OTC drugs are mainly established drugs with long histories of use and are deemed to be safe to be taken without supervision by physicians.

There is a further differentiation of ethical drugs into new drugs (those covered by patents) and generics (copies of drugs that have expired patents – refer to Case Study #10.2). Most of the descriptions in this book apply to new drugs.

1.2 AN OVERVIEW OF THE DRUG DISCOVERY TO APPROVAL PROCESS

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

Today, personnel from many fields are involved in the process of drug discovery and development, namely, scientists, cl...