Pharmaceutical engineering

Erlich had found that Atoxyl, an arsenic-containing compound which is harmful to humans, was very effective at killing Treponema pallidum, the bacteria which causes syphilis.

He hypothesized that if the structure of Atoxyl was altered, a "magic bullet" could potentially be identified which would kill the parasitic bacteria without having any adverse effects on human health.

[4] In 1928, Alexander Fleming discovered a mold named Penicillium chrysogenum which prevented many types of bacteria from growing.

Scientists with major chemical companies such as Pfizer were able to develop a deep-fermentation process which could produce a high yield of penicillin.

In 1944, Pfizer opened the first penicillin factory, and its products were exported to aid the war efforts overseas.