The renewal of chemistry

The renewal of chemistry - The 18th century concluded its progress in chemistry with an enthusiastic environment. Joseph Priestley in the United Kingdom, Carl Wilhelm Scheele in Sweden, Antoine Laurent de Lavoisier in France, 2 gave a precise signifi cation to the chemical reactivity and promoted a large number of substances to the statute of chemical reagents. Scheele and Priestley prepared and studied oxygen. Both of them discovered nitrogen as a constituent of air, carbon monoxide, ammonia, and several other gases ; manganese, barium and chlorine; isolated glycerin and many acids, including tartaric, lactic, uric, prussic, citric, and gallic. Lavoisier is generally considered as the founder of modern chemistry as creating the oxygen theory of combustion. 3 He should be known as one of the most astonishing 18th century “ men of the Enlightenment, ” the founder of modern scientifi experimental methodology. By formulating the principle of the conservation of mass, he gave a clear differentiation between elements and compounds, something so important for pharmaceutical chemistry.

Renewal of Chemistry

The Experiment

Few years later, Antoine François de Fourcroy, Louis Nicolas Vauquelin, Joseph Louis Proust, Jöns Jakob Berzelius, Louis-Joseph Gay-Lussac, and Humphrey Davy introduced new concepts in chemistry. Those scientists integrated the practical advancements of a new generation of experimenters. All these industrial innovations would have their own impact on other developments in industrial and then medicinal chemistry. 4 At the turn of the 19th century, as the result of a scientific approach, drugs are becoming an industrial item. Claude Louis Berthollet began the industrial exploitation of chlorine (1785). Nicolas Leblanc prepared sodium hydroxide (1789) and then, bleach (1796).

Davy performed electrolysis and distinguished between acids and anhydrides. Louis Jacques Thénard prepared hydrogen peroxide and Antoine Jérôme Balard discovered bromide (1826). The growing of therapeutic resources was mainly due to the mastery of chemical or physico-chemical principles  proposed by Gay-Lussac and Justus Von Liebig. 5 This chemists ’ generation, by realizing all these discoveries, established the compost of the therapeutic discoveries of the 19th century. The constitution of chemistry as a scientifi c discipline found a new turn few decades later by crossing the road of biology which included revolutionary works of ClaudeBernard, 6 Rudolph Virchow, 7 and Lo uis  Pasteur. 8 Besides these fundamental sciences, physiology, biochemistry, or microbiology were becoming natural tributaries of the outbreak of pharmacology. Thus, rational treatments were about to be designed on the purpose of new knowledge in various clinical or fundamental fi elds. After a period characterized by extraction and purifi cation from natural materials (mainly plants), drugs would be synthesized in chemical factories or prepared through biotechnology (fermentation or gene technology) after a rational research, design and developmentin research laboratories.

Whereas the purpose was to isolate active molecules from plants during the fi rst half of the 19th century, the birth of organic chemistry following charcoal and oil industries, progressively led chemists and pharmacists toward organic synthesis performed in what would be called “ laboratory ” a new concept created by this generation of scientists. Even when those laboratories hosted discoveries like active principles extracted from plants, progresses in drug compounding and packaging made irreversible industrialization processes. At the same time, the economical dimension of growing pharmaceutical industry transformed drugs as strategic items, mainly when it could interfere with military processes, for instance during colonial expeditions.