United Therapeutics Corp specializes in drug development for pulmonary arterial hypertension (PAH), a rare and progressive disease marked by abnormally high blood pressure in the arteries of the lungs. The company's therapies for PAH largely focus on the prostacyclin pathway, and many of its treatments are based on the same molecule, treprostinil. The company markets and sells the following commercial therapies in the United States to treat PAH: Tyvaso DPI (treprostinil) Inhalation Powder, Remodulin Injection, Orenitram (treprostinil) Extended-Release Tablets, Adcirca (tadalafil) Tablets, and Unituxin. In addition, it is developing a pipeline of projects that includes new indications and delivery devices for existing products and new products to treat PAH and other conditions.