Maryland-based United Therapeutics is planning a major expansion of its research-and-manufacturing facility in Research Triangle Park, N.C., that will allow it to triple its already 100-plus local work force, according to Newsobserver.com.

United wants to build a 177,000-square-foot expansion at its campus, which encompasses 55 acres, as well as a 173,635-square-foot parking deck, according to plans. The addition will increase the ability to manufacture, package and label drugs, as well as warehouse capacity. After opening its 200,000-square-foot research and manufacturing facility in RTP in early 2009, United won regulatory approval for two drugs that treat pulmonary hypertension, Tyvaso and Adcirca. United generated $437.4 million in revenue for the nine months ended Sept. 30, up 74% from the year-ago period.