Biomedical Engineering Reference
In-Depth Information
The fi rst stages of development of the modern pharmaceutical industry can be traced back to the
turn of the twentieth century. At that time (apart from folk cures), the medical community had at
their disposal only four drugs that were effective in treating specifi c diseases:
•
Digitalis (extracted from foxglove) was known to stimulate heart muscle and, hence, was used
to treat various heart conditions.
•
Quinine, obtained from the barks/roots of a plant (
Cinchona
genus), was used to treat malaria.
•
Pecacuanha (active ingredient is a mixture of alkaloids), used for treating dysentery, was ob-
tained from the bark/roots of the plant genus
Cephaelis
.
•
Mercury, for the treatment of syphilis.
This lack of appropriate, safe and effective medicines contributed in no small way to the low life
expectancy characteristic of those times.
Developments in biology (particularly the growing realization of the microbiological basis of
many diseases), as well as a developing appreciation of the principles of organic chemistry, helped
underpin future innovation in the fl edgling pharmaceutical industry. The successful synthesis of
various artifi cial dyes, which proved to be therapeutically useful, led to the formation of pharma-
ceutical/chemical companies such as Bayer and Hoechst in the late 1800s. Scientists at Bayer, for
example, succeeded in synthesizing aspirin in 1895.
Despite these early advances, it was not until the 1930s that the pharmaceutical industry
began to develop in earnest. The initial landmark discovery of this era was probably the
discovery, and chemical synthesis, of the sulfa drugs. These are a group of related molecules
derived from the red dye
prontosil rubrum
. These drugs proved effective in the treatment
of a wide variety of bacterial infections (Figure 1.1). Although it was first used therapeuti-
cally in the early 1920s, large-scale industrial production of insulin also commenced in the
1930s.
The medical success of these drugs gave new emphasis to the pharmaceutical industry, which
was boosted further by the commencement of industrial-scale penicillin manufacture in the early
1940s. Around this time, many of the current leading pharmaceutical companies (or their fore-
runners) were founded. Examples include Ciba Geigy, Eli Lilly, Wellcome, Glaxo and Roche.
Over the next two to three decades, these companies developed drugs such as tetracyclines, cor-
ticosteroids, oral contraceptives, antidepressants and many more. Most of these pharmaceutical
substances are manufactured by direct chemical synthesis.
1.4 The age of biopharmaceuticals
Biomedical research continues to broaden our understanding of the molecular mechanisms un-
derlining both health and disease. Research undertaken since the 1950s has pinpointed a host of
proteins produced naturally in the body that have obvious therapeutic applications. Examples in-
clude the interferons and interleukins (which regulate the immune response), growth factors, such
as erythropoietin (EPO; which stimulates red blood cell production), and neurotrophic factors
(which regulate the development and maintenance of neural tissue).
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