Citrocarbonate was one of the first Upjohn products that was based on scientific research. It was used to treat indigestion. Fred Heyl, the first scientist hired, received a patent for "Effervescent alkali compounds and processes of manufacturing and preparing the same" on 17 February 1925. The original copy of the patent is shown below with the assignment of it by Fred to The Upjohn Company. It expired after 17 years but Upjohn manufactured citrocarbonate in their Portage plant into the 1980s.

The photos below are Citrocarbonate production in the 1930s. This location is likely Building 25, which later became the research tower but was originally built for manufacturing and used for such until all manufacturing moved to Portage during 1948 to 1951.