Dr. Jan Constant Janssen (18 September 1895 – 15 April 1970) was a

Belgian Belgian may refer to: * Something of, or related to, Belgium * Belgians, people from Belgium or of Belgian descent * Languages of Belgium, languages spoken in Belgium, such as Dutch, French, and German *Ancient Belgian language, an extinct languag ...

physician and businessman. He was the third child (out of four) of Adriaan Victor Janssen (1854–1942) and Anna Catharina Eelen (1855–1929). He went to high school in

Hoogstraten Hoogstraten () is a municipality located in the Belgian province of Antwerp. The municipality comprises Hoogstraten, Meer, Meerle, Meersel-Dreef, Minderhout and Wortel (Meersel-Dreef includes the northernmost point in Belgium). Hoogstraten (o ...

and studied medicine at the

Catholic University of Leuven University of Leuven or University of Louvain (french: Université de Louvain, link=no; nl, Universiteit Leuven, link=no) may refer to: * Old University of Leuven (1425–1797) * State University of Leuven (1817–1835) * Catholic University of ...

and the

University of Ghent Ghent University ( nl, Universiteit Gent, abbreviated as UGent) is a public research university located in Ghent, Belgium. Established before the state of Belgium itself, the university was founded by the Dutch King William I in 1817, when the ...

. On 16 April 1925, he married Margriet Fleerackers (5 January 1897 – 23 September 1973), together they had four children. Their oldest son,

Paul Janssen Paul Adriaan Jan, Baron Janssen (12 September 1926 - 11 November 2003) was a Belgian physician. He was the founder of Janssen Pharmaceutica, a pharmaceutical company with over 20,000 employees which is now a subsidiary of Johnson & Johnson. Ea ...

, would become one of the most successful scientists in pharmaceutics.

Career

He started his career as a family physician in

Turnhout Turnhout () is a Belgium, Belgian Municipalities in Belgium, municipality and city located in the Flemish Region, Flemish Provinces of Belgium, province of Antwerp (province), Antwerp. The municipality comprises only the city of Turnhout proper. ...

, but in addition he was interested in business too. In 1921, he met Ladislas Richter in

Vienna en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...

, who was the son of Gedeon Richter, who owned a pharmaceutical factory in

Budapest Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population ...

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia a ...

. In 1933, he acquired the right to distribute the pharmaceutical products of Richter, the Hungarian pharmaceutical company, for Belgium, the

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and

Belgian Congo The Belgian Congo (french: Congo belge, ; nl, Belgisch-Congo) was a Belgian colony in Central Africa from 1908 until independence in 1960. The former colony adopted its present name, the Democratic Republic of the Congo (DRC), in 1964. Colo ...

. On 23 October 1934, he founded the ''N.V. Produkten Richter'' in

. In 1937 Constant Janssen acquired an old factory building in the ''Statiestraat 78'' in

for his growing company, which he expanded during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

into a four-storey building. In 1938 he closed his practice as a family physician and concentrated his effort of the expansion of his pharmaceutical business. His wife managed the production, quality control, and the administration of the company. Still a medical student, his son Paul Janssen helped with the development of Perdolan. After

, the brandname of the products was changed into ''Eupharma'', and later the company would evolve into

Janssen Pharmaceutica Janssen Pharmaceuticals is a pharmaceutical company headquartered in Beerse, Belgium, and wholly-owned by Johnson & Johnson. It was founded in 1953 by Paul Janssen. In 1961, Janssen Pharmaceuticals was purchased by New Jersey-based American ...

Sources

* Dirk Collier (Ed.), ''Dr. Constant Janssen'', Janssen Pharmaceutica, 1996 {{DEFAULTSORT:Janssen, Constant 1895 births 1970 deaths 20th-century Belgian businesspeople Belgian general practitioners People from Beerse People from Turnhout Belgian pharmacists