A Liquid Chromatography–Mass Spectrometry (LC-MS/MS) Method For The Quantification Of Rapamycin In Porcine Whole Blood And Tissues

By Zahuindanda M. DeForrest, Scott D. McConkie, Peter J. Mann, and Melissa M. Kiser

Rapamycin, also known as Sirolimus, was discovered in 1965, when it was isolated from a microorganism in soil. Since its discovery, it has demonstrated useful immunosuppressive properties, which have been utilized in preventing the rejection of organ transplants. Rapamycin is a mTOR inhibitor that has an advantage over calcineurin inhibitors, such as tacrolimus and cyclosporine, since it is not toxic to kidneys. Rapamycin has a molecular weight of 914 and has the molecular formula of C51H79NO13.

BASi developed and validated an LC-MS/MS method for the quantification of rapamycin in porcine whole blood and tissues. The validation included the assessment of linearity, within-run and between-run precision and accuracy, specificity, freeze/thaw stability, short-term (room temperature) stability, the effect of dilution, and extraction efficiency. The method is suitable for analysis of samples over the range 0.1 - 100 ng/mL in porcine whole blood and 0.5 - 500 ng/mL in porcine myocardial, liver, lung, and kidney tissues.