Paul Janssen

Paul Adriaan Jan, Baron Janssen (12 September 1926, Turnhout – 11 November 2003, Rome) was a Belgian physician. He was the founder of Janssen Pharmaceutica, a pharmaceutical company with over 20,000 employees.

Paul Janssen was the son of Constant Janssen and Margriet Fleerackers. On 16 April 1957, he married Dora Aerts.

He attended secondary school at the Jesuit St Jozef college in Turnhout, after which he decided to follow in his father's footsteps and become a physician. During World War II, Janssen studied physics, biology and chemistry at the Facultés universitaires Notre-Dame de la Paix (FUNDP) in Namur. He then studied medicine at the Catholic University of Leuven and the University of Ghent. In 1951, Janssen received his medical degree magna cum laude from Ghent University. He also obtained a postdoctoral degree in pharmacology at the same university in 1956, and studied at the Institute of Pharmacology of the University of Cologne.

During his military service, he worked at the University of Cologne in Germany at the Institute of Pharmacology of J. Schuller, where he worked until 1952. After he returned to Belgium he worked part-time at the Institute of Pharmacology and Therapeutics (University of Ghent) of Professor Corneille Heymans, who had won the Nobel Prize for medicine in 1938. Janssen founded his own research laboratory in 1953, with a loan of 50,000 Belgian francs from his father. In 1953 he also discovered his first drug ambucetamide, an antispasmodic found to be particularly effective for the relief of menstrual pain.

In 1956, Janssen received his teaching certificate for higher education in pharmacology (the habilitation and the official pro venia legendi (Latin, for permission to lecture)) with a thesis on Compounds of the R 79 type. He then left the university and in 1956 established the company which would become Janssen Pharmaceutica. On 11 February 1958 he made haloperidol a major breakthrough in the treatment of schizophrenia. Paul Janssen and his team developed the fentanyl family of drugs, and many other anesthesia-related drugs, such as droperidol and etomidate which made a significant contribution to anesthesiology.One of the drugs he developed for the treatment of diarrhea, Diphenoxylate (Lomotil) was used during the Apollo program. In 1985, his company was the first Western pharmaceutical company to set up a pharmaceutical factory in the People's Republic of China (Xi'an). In 1995 he founded the Center for Molecular Design, together with Paul Lewi, where he and his team used a supercomputer to search for candidate molecules to find a treatment for AIDS.

Janssen and the scientists at Janssen Pharmaceutica discovered more than 80 new medicines. Four of his medicines are on the WHO list of essential medicines; this is an absolute world record. The majority of the drugs he and his teams developed were for human medicine and are being used to treat infestations by fungi and worms, mental illnesses, cardiovascular diseases, allergies, and gastrointestinal disorders.

In 1991, he was raised into the Belgian nobility by King Baudouin of Belgium and given the personal title of Baron.

Paul Janssen died in Rome, Italy, in 2003, while attending the celebration of the 400th anniversary of the founding of the Pontifical Academy of Sciences, of which he had been a member since 1990. He was survived by his widow, Dora Aerts Janssen, two sons, three daughters and 13 grandchildren.

• In 2005 he finished as runner up, after Father Damien, in the poll for The Greatest Belgian organized by the regional Flemish television.
• On Wednesday 22 October 2008, Paul Janssen was awarded the title of Most Important Belgian Scientist, an initiative of the Eos magazine.