March 6, 1899: Bayer patents the ‘wonder drug’ Aspirin.

On this day 117 years ago, the Imperial Patent Office in Berlin conceded the German pharmaceutical company Friedrich Bayer & Co. the patent for Aspirin, its chosen brand name for acetylsalicylic acid, a painkilling drug. In no time it would become the most common drug in households all over the world.

In its primitive form, salicylic acid had been part of common folk medicines for a long time, as it can be found in the bark of several trees (e.g. willow trees), in certain fruits, grains and vegetables. Hippocrates, for example, told his patients to drink willow-leaf tea or chew bits of willow bark, as this would relieve pain and reduce fever. A closer study of the bark’s property began in the 18^th century, and a chemical investigation of its healing powers was pursued in earnest when Napoleon’s continental blockade prevented the import of Peruvian cinchona-tree bark (another natural source of salicylic acid), already in medicinal use. Salicin, extracted from the willow bark, was eventually commercialised by the German Heyden Chemical Company for the treatment of pain and fever. Unfortunately, a prolonged intake of this drug serverely upset the stomach, causing nausea, vomiting, bleeding and ulcers.

Acetylsalicylic acid crystals. By Steve Mike Neef.

In 1895, Arthur Eichengrün (1867-1949), head of Bayer’s chemistry research laboratory, gave Felix Hoffmann (1868-1946), a chemist at the lab, the task of finding a form of salicylic acid that had all its benefits but none of the negative side-effects. Hoffmann, whose rheumatic father was one of the victims of these negative drug effects, managed to chemically modify salicylic acid in 1897. The result was acetylsalicylic acid, a derivative that could be easily absorbed by the human body without losing any of the therapeutical benefits of the original drug. Unfortunately, Heinrich Dreser, the chemist in charge of the standardised testing of pharmaceutical agents, did not believe in the superior quality of this new drug and refused to do further testing. Eichengrün then sent the drug to various local hospitals. Their feed-back left no doubt as to the superiority of this analgesic in relation to other salicylates then in use. Under pressure, Dreser had to relent and proceed with the testing. Ironically, it was he who in 1899 published the first article on Aspirin and its benefits in the journals Die Heilkunde and Therapeutische Monatshefte.

Archives of Bayer AG

On March 6 that year, Bayer received the patent rights for Aspirin. The brand name, incidentally, derived from ‘a’ for ‘acetyl’, ‘spir’ from the ‘spiraea’ plant (a source of salicin) and the suffix ‘in’, typical of medicine names. Bayer at once began to sell the drug in powdered form. In 1900, Aspirin appeared for the first time in tablet form on the market, which greatly helped its popularity. In 1915, Aspirin could be bought without a prescription, thus becoming one of the first over-the-counter, mass market household drugs in the world. It changed the way both doctors and patients dealt with pain and illness.

In the 1930s, Bayer credited Felix Hoffmann with the invention of Aspirin, although research in the 1990s proved that the leading chemist Arthur Eichengrün, of Jewish origin, had been a key figure from the beginning of Hoffmann’s research to Aspririn’s final success. More on this controversy: Walter Sneader’s report, Bayer’s press release or “Edward Stone and aspirin“.

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