Sensitive quantification of sirolimus and everolimus by LC-MS/MS with online sample cleanup.

Sirolimus and its derivative everolimus are widely used today as immunosuppressive agents for example in the transplantation medicine. The problematic pharmacokinetic behavior of those substances makes therapeutic drug monitoring mandatory. Therefore, a fast, simple and sensitive high-throughput procedure using online extraction with turbulent flow chromatography for the concurrent measurement of sirolimus and everolimus has been developed. 200 microl of whole blood was mixed with internal standard (23-desmethoxyrapamycin) and the precipitation solution and centrifuged. An aliquot of the supernatant was transferred into autosampler vials. 50 microl of the supernatant was injected into the LC system, where the analytes were extracted using turbulent flow chromatography and thereafter analyzed using reversed phase chromatography. Detection was done by atmospherical pressure chemical ionization (APCI) mass spectrometry in the negative ionization mode. The method has been fully validated and compared to a previously used method. The method was shown to be linear over the entire calibration range (2.2-43.7 microg/l for everolimus and 2.9-51.2 microg/l for sirolimus). The lower limit of quantification was 0.5 microg/l for both compounds. For within-day and between-day analysis, the CV's were <7.6% for everolimus and <8.7% for sirolimus, respectively. The accuracy was between 92.1% and 105% for everolimus and 96.1% and 106% for sirolimus. Recovery ranged between 46.3% and 50.6% for everolimus and 51.2% and 57.2% for sirolimus. The method was demonstrated to be free of matrix effects and comparable to the previously used method. The presented LC-MS/MS method, using turbulent flow chromatography online extraction, allows a fast, simple and reliable determination of everolimus and sirolimus.

Mueller DM ，Rentsch KM 《-》

Ultra fast liquid chromatography-tandem mass spectrometry routine method for simultaneous determination of cyclosporin A, tacrolimus, sirolimus, and everolimus in whole blood using deuterated internal standards for cyclosporin A and everolimus.

Meinitzer A ，Gartner G ，Pilz S ，Stettin M ... -  《-》

Robust, high-throughput LC-MS/MS method for therapeutic drug monitoring of cyclosporine, tacrolimus, everolimus, and sirolimus in whole blood.

Koster RA ，Dijkers EC ，Uges DR 《-》

High-throughput analysis of everolimus (RAD001) and cyclosporin A (CsA) in whole blood by liquid chromatography/mass spectrometry using a semi-automated 96-well solid-phase extraction system.

McMahon LM ，Luo S ，Hayes M ，Tse FL ... -  《RAPID COMMUNICATIONS IN MASS SPECTROMETRY》

Comparison of a stable isotope-labeled and an analog internal standard for the quantification of everolimus by a liquid chromatography-tandem mass spectrometry method.

Heideloff C ，Payto D ，Wang S 《-》