The purpose of this study is to evaluate the effect of esomeprazole, a proton pump inhibitor, on treprostinil pharmacokinetics.

This open-label study will evaluate the effect of esomeprazole, a proton pump inhibitor, on treprostinil pharmacokinetics following a single 1 mg oral dose of UT-15C SR in healthy volunteers.

Inclusion Criteria:

• Subject is healthy and between the ages of 18 and 55 years, inclusive, at Screening.
• Female subjects must weigh between 45 and 100 kg, inclusive, with a BMI between 19.0-29.9 kg/m2, inclusive at Screening. Male subjects must weigh between 50 and 120 kg, inclusive, with a BMI between 19.0-32.0 kg/m2, inclusive at Screening.
• Subject has a medical history, physical examination, vital signs, ECG and clinical laboratory results within normal limits or considered not clinically significant by the Investigator at Screening.

Exclusion Criteria:

• Subject has any clinically relevant abnormality identified during the screening physical examination, 12-lead ECG, or laboratory examinations.
• Subject has a history of anaphylaxis, a documented hypersensitivity reaction, or a clinically significant idiosyncratic reaction to any drug.
• Subject has a clinically significant history of neurological, cardiovascular, respiratory, endocrine, hematological, hepatic, renal, gastrointestinal, genitourinary, pulmonary, and/or musculoskeletal disease; glaucoma; a psychiatric disorder, or any other chronic disease, whether controlled by medication or not.