Drug Discovery and Development - E-Book

Technology in Transition

Raymond G Hill

• Publisher: Churchill Livingstone
• Year: 2012
• ISBN:
  9780702053160
• Edition: 2
• Topic: Medicine
• Subtopic: Pharmacology

The modern pharmacopeia has enormous power to alleviate disease, and owes its existence almost entirely to the work of the pharmaceutical industry. This book provides an introduction to the way the industry goes about the discovery and development of new drugs. The first part gives a brief historical account from its origins in the mediaeval apothecaries' trade, and discusses the changing understanding of what we mean by disease, and what therapy aims to achieve, as well as summarising case histories of the discovery and development of some important drugs. The second part focuses on the science and technology involved in the discovery process: the stages by which a promising new chemical entity is identified, from the starting point of a medical need and an idea for addressing it. A chapter on biopharmaceuticals, whose discovery and development tend to follow routes somewhat different from synthetic compounds, is included here, as well as accounts of patent issues that arise in the discovery phase, and a chapter on research management in this environment. The third section of the book deals with drug development: the work that has to be undertaken to turn the drug candidate that emerges from the discovery process into a product on the market.

• The definitive introduction to how a pharmaceutical company goes about its business of discovering and developing drugs.
  
  

  The second edition has a new editor: Professor Raymond Hill? non-executive director of Addex Pharmaceuticals, Covagenand of Orexo AB? Visiting Industrial Professor of Pharmacology in the University of Bristol? Visiting Professor in the School ofMedical and Health Sciences at the University of Surrey? Visiting Professor in Physiology and Pharmacology at the University of Strathclyde? President and Chair of theCouncil of the British Pharmacological Society? member of the Nuffield Council on Bioethics and the Advisory Council on Misuse of Drugs.
  
  

  New to this edition:
  
  

  • Completely rewritten chapter on The Role of Medicinal Chemistry in the Drug Discovery Process.
  • New topic - DMPK Optimization Strategy in drug discovery.
  • New chapter on Scaffolds: Small globular proteins as antibody substitutes.
  • Totally updated chapters on Intellectual Property and Marketing
  • 50 new illustrations in full colour

  Features
  
  

  • Accessible, general guide to pharmaceutical research and development.
  • Examines the interfaces between cost and social benefit, quality control and mass production, regulatory bodies, patent management, and all interdisciplinary intersections essential to effective drug development.
  • Written by a strong team of scientists with long experience in the pharmaceutical industry.
  • Solid overview of all the steps from lab bench to market in an easy-to-understand way which will be accessible to non-specialists.

  From customer reviews of the previous edition:
  
  

  '… it will have everything you need to know on this module. Deeply referenced and, thus, deeply reliable.
  
  

  • Highly Commended in the medicine category of the BMA 2006 medical book competition
  • Winner of the Royal Society of Medicine Library Prize for Medical Book of the Year

Chapter 1 The development of the pharmaceutical industry

H P. Rang

Antecedents and origins

Our task in this book is to give an account of the principles underlying drug discovery as it happens today, and to provide pointers to the future. The present situation, of course, represents merely the current frame of a long-running movie. To understand the significance of the different elements that appear in the frame, and to predict what is likely to change in the next few frames, we need to know something about what has gone before. In this chapter we give a brief and selective account of some of the events and trends that have shaped the pharmaceutical industry. Most of the action in our metaphorical movie happened in the last century, despite the film having started at the birth of civilization, some 10 000 years ago. The next decade or two will certainly see at least as much change as the past century.

Many excellent and extensive histories of medicine and the pharmaceutical industry have been published, to which readers seeking more detailed information are referred (Mann, 1984; Sneader, 1985; Weatherall, 1990; Porter, 1997; see also Drews, 2000, 2003).

Disease has been recognized as an enemy of humankind since civilization began, and plagues of infectious diseases arrived as soon as humans began to congregate in settlements about 5000 years ago. Early writings on papyrus and clay tablets describe many kinds of disease, and list a wide variety of herbal and other remedies used to treat them. The earliest such document, the famous Ebers papyrus, dating from around 1550BC, describes more than 800 such remedies. Disease was in those times regarded as an affliction sent by the gods; consequently, the remedies were aimed partly at neutralizing or purging the affliction, and partly at appeasing the deities. Despite its essentially theistic basis, early medicine nevertheless discovered, through empiricism and common sense, many plant extracts whose pharmacological properties we recognize and still use today; their active principles include opium alkaloids, ephedrine, emetine, cannabis, senna and many others¹.

In contrast to the ancient Egyptians, who would, one feels, have been completely unsympathetic to medical science had they been time-warped into the 21st century, the ancient Greeks might have felt much more at home in the present era. They sought to understand nature, work out its rules and apply them to alleviate disease, just as we aim to do today. The Hippocratic tradition had little time for theistic explanations. However, the Greeks were not experimenters, and so the basis of Greek medicine remained essentially theoretical. Their theories were philosophical constructs, whose perceived validity rested on their elegance and logical consistency; the idea of testing theory by experiment came much later, and this aspect of present-day science would have found no resonance in ancient Greece. The basic concept of four humours – black bile, yellow bile, blood and phlegm – proved, with the help of Greek reasoning, to be an extremely versatile framework for explaining health and disease. Given the right starting point – cells, molecules and tissues instead of humours – they would quickly have come to terms with modern medicine. From a therapeutic perspective, Greek medicine placed rather little emphasis on herbal remedies; they incorporated earlier teachings on the subject, but made few advances of their own. The Greek traditions formed the basis of the prolific writings of Galen in the 2nd century AD, whose influence dominated the practice of medicine in Europe well into the Renaissance. Other civilizations, notably Indian, Arabic and Chinese, similarly developed their own medical traditions, which – unlike those of the Greeks – still flourish independently of the Western ones.

Despite the emphasis on herbal remedies in these early medical concepts, and growing scientific interest in their use as medicines from the 18th century onwards, it was only in the mid-19th century that chemistry and biology advanced sufficiently to give a scientific basis to drug therapy, and it was not until the beginning of the 20th century that this knowledge actually began to be applied to the discovery of new drugs. In the long interim, the apothecary’s trade flourished; closely controlled by guilds and apprenticeship schemes, it formed the supply route for the exotic preparations that were used in treatment. The early development of therapeutics – based, as we have seen, mainly on superstition and on theories that have been swept away by scientific advances – represents prehistory as far as the development of the pharmaceutical industry is concerned, and there are few, if any, traces of it remaining².

Therapeutics in the 19th century

Although preventive medicine had made some spectacular advances, for example in controlling scurvy (Lind, 1763) and in the area of infectious diseases, vaccination (Jenner, 1798), curtailment of the London cholera epidemic of 1854 by turning off the Broad Street Pump (Snow), and control of childbirth fever and surgical infections using antiseptic techniques (Semmelweis, 1861; Lister, 1867), therapeutic medicine was virtually non-existent until the end of the 19th century.

Oliver Wendell Holmes – a pillar of the medical establishment – wrote in 1860: ‘I firmly believe that if the whole materia medica, as now used, could be sunk to the bottom of the sea, it would be all the better for mankind – and the worse for the fishes’ (see Porter, 1997). This may have been a somewhat ungenerous appraisal, for some contemporary medicines – notably digitalis, famously described by Withering in 1785, extract of willow bark (salicylic acid), and Cinchona extract (quinine) – had beneficial effects that were well documented. But on balance, Holmes was right – medicines did more harm than good.

We can obtain an idea of the state of therapeutics at the time from the first edition of the British Pharmacopoeia, published in 1864, which lists 311 preparations. Of these, 187 were plant-derived materials, only nine of which were purified substances. Most of the plant products – lemon juice, rose hips, yeast, etc. – lacked any components we would now regard as therapeutically relevant, but some – digitalis, castor oil, ergot, colchicum – were pharmacologically active. Of the 311 preparations, 103 were ‘chemicals’, mainly inorganic – iodine, ferrous sulfate, sodium bicarbonate, and many toxic salts of bismuth, arsenic, lead and mercury – but also a few synthetic chemicals, such as diethyl ether and chloroform. The remainder comprised miscellaneous materials and a few animal products, such as lard, cantharidin and cochineal.

An industry begins to emerge

For the pharmaceutical industry, the transition from prehistory to actual history occurred late in the 19th century (3Q19C, as managers of today might like to call it), when three essential strands came together. These were: the evolving science of biomedicine (and especially pharmacology); the emergence of synthetic organic chemistry; and the development of a chemical industry in Europe, coupled with a medical supplies trade – the result of buoyant entrepreneurship, mainly in America.

Developments in biomedicine

Science began to be applied wholeheartedly to medicine – as to almost every other aspect of life – in the 19th century. Among the most important milestones from the point of view of drug discovery was the elaboration in 1858 of cell theory, by the German pathologist Rudolf Virchow. Virchow was a remarkable man: pre-eminent as a pathologist, he also designed the Berlin sewage system and instituted hygiene inspections in schools, and later became an active member of the Reichstag. The tremendous reductionist leap of the cell theory gave biology – and the pharmaceutical industry – the scientific foundation it needed. It is only by thinking of living systems in terms of the function of their cells that one can begin to understand how molecules affect them.

A second milestone was the birth of pharmacology as a scientific discipline when the world’s first Pharmacological Institute was set up in 1847 at Dorpat by Rudolf Buchheim – literally by Buchheim himself, as the Institute was in his own house and funded by him personally. It gained such recognition that the university built him a new one 13 years later. Buchheim foresaw that pharmacology as a science was needed to exploit the knowledge of physiology, which was being advanced by pioneers such as Magendie and Claude Bernard, and link it to therapeutics. When one remembers that this was at a time when organic chemistry and physiology were both in their cradles, and therapeutics was ineffectual, Buchheim’s vision seems bold, if not slightly crazy. Nevertheless, his Institute was a spectacular success. Although he made no truly seminal discoveries, Buchheim imposed on himself and his staff extremely high standards of experimentation and argument, which eclipsed the empiricism of the old therapeutic principles and attracted some exceptionally gifted students. Among these was the legendary Oswald Schmiedeberg, who later ...