Quantification of treprostinil concentration in rat and human using a novel validated and rapid liquid chromatography-tandem mass spectrometry method: Experimental and clinical applications in ischemia-reperfusion injury.

Treprostinil (Remodulin®) is a Food and Drug Administration (FDA) approved prostacyclin analog to treat pulmonary arterial hypertension. Recently, treprostinil has been investigated to reduce ischemia-reperfusion injury (IRI) during transplantation, which currently has no approved treatment. A validated analytical method is necessary to measure treprostinil concentrations in biological specimens. Here, a novel, sensitive, and specific method to measure treprostinil concentrations in rat serum, human serum, and human plasma has been developed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Biological samples were processed by protein precipitation before chromatography and 6-keto Prostaglandin F1α-d4 was used as an internal standard. A gradient method was established with a total run time of 4 min. The assay was linear over the range of 0.25-75.0 ng/ml with accuracy (92.97-107.87 %), intra-assay precision (1.16-3.34 %), and inter-assay precision (1.11-4.58 %) in all biological matrices, which are within FDA acceptance criteria. No significant variation in treprostinil or 6-keto Prostaglandin F1α-d4 concentrations were observed under the investigated storage conditions. This novel, sensitive, and specific LC/MS-MS method is cost-effective and suitable for measuring treprostinil concentrations in animal studies and human biological samples for clinical applications.