Otsuka Pharmaceutical Companies (U.S.) is the US arm of Japan's Otsuka group, made up of Otsuka America Pharmaceutical, Inc. (OAPI, created in 1989) and Otsuka Pharmaceutical Development & Commercialization (OPDC). Headquartered in Princeton, New Jersey, with R&D in Rockville, Maryland, it develops and commercializes medicines with a focus on neuroscience, nephrology and other areas of unmet need.