Evaluation of a rapid method for the therapeutic drug monitoring of aliskiren, enalapril and its active metabolite in plasma and urine by UHPLC-MS/MS.

Given the increasing popularity of aliskiren, particularly in combination with angiotensin converting enzyme inhibitor (e.g. enalapril), it is important to determine whether its use in combination with these agents is associated with potentially life threatening safety events. Analytical methods for the simultaneous determination of both drugs in plasma and urine utilized in clinical studies on efficacy and safety have not been fully described in the literature. In this work, a new, fast and reliable method using a digitally controlled microextraction by packed sorbent (eVol(®)-MEPS) followed by ultra-high performance liquid chromatography (UHPLC) coupled with tandem mass spectrometry (MS/MS) was developed and validated to quantify an aliskiren, enalapril and its active metabolite in both human plasma and urine. Chromatographic separation was accomplished on a Poroshell 120 EC-C18 column with a gradient elution system consisting of 0.1% formic acid in water and acetonitrile (1.5min of total analysis). Detection was performed by multiple reaction monitoring (MRM) mode using electrospray ionization in the positive ion mode. This assay method has been fully validated in terms of selectivity, linearity, accuracy, precision, stability, recovery and matrix effect. The developed method can be applied to the routine determination of selected compounds in human plasma and urine and can be useful to elucidate the mechanisms of the potential risks triggered by the combination of aliskiren and enalapril as well as its active metabolite enalaprilat.

Magiera S ，Kusa J 《-》

Simultaneous quantitative and qualitative analysis of aliskiren, enalapril and its active metabolite enalaprilat in undiluted human urine utilizing LC-ESI-MS/MS.

The benefit-risk ratio of combined blocking by the direct renin inhibitor aliskiren and an angiotensin-converting enzyme inhibitor (e.g. enalapril) on the renin-angiotensin-aldosterone system is discussed. No method was available for simultaneous determination of both drugs in urine. A novel sensitive method for simultaneous quantification in undiluted human urine was developed which enables systematic pharmacokinetic investigations, especially in poorly investigated populations like children. Matrix effects were clearly reduced by applying solid-phase extraction followed by a chromatographic separation on Xselect(TM) C18 CSH columns. Mobile phase consisted of methanol and water, both acidified with formic acid. Under gradient conditions and a flow rate of 0.4 mL/min the column effluent was monitored by tandem mass spectrometry with electrospray ionization. Calibration curves were constructed in the range of 9.4-9600 ng/mL regarding aliskiren, 11.6-12000 ng/mL for enalapril and 8.8-9000 ng/mL for enalaprilat. All curves were analyzed utilizing 1/x(2) -weighted quadratic squared regression. Intra-run and inter-run precision were 3.2-5.8% and 6.1-10.3% for aliskiren, 2.4-6.1% and 3.9-7.9% for enalapril as well as 3.1-9.4% and 4.7-12.7% regarding enalaprilat. Selectivity, accuracy and stability results comply with current international bioanalysis guidelines. The fully validated method was successfully applied to a pharmacokinetic investigation in healthy volunteers.

Burckhardt BB ，Tins J ，Laeer S 《-》

Fast, simultaneous quantification of three novel cardiac drugs in human urine by MEPS-UHPLC-MS/MS for therapeutic drug monitoring.

A sensitive and selective ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was developed for the fast, simultaneous quantification of three novel cardiac drugs (aliskiren, prasugrel and rivaroxaban) in human urine. Sample preparation was performed with microextraction with packed sorbent (MEPS), which is a miniaturization of solid phase extraction. The optimal conditions for MEPS extraction were obtained using C8 sorbent, small sample volumes and a short time period (about 3min for the entire sample preparation step). Chromatographic separation of the selected compounds was achieved in less than 1.5min on a Zorbax Rapid Resolution High Definition SB-C18 column using isocratic elution with 0.1% formic acid and acetonitrile (70:30, v/v) at a flow rate of 0.8mLmin(-1). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via an electrospray ionization source with positive ionization mode. The method was fully validated according to the latest recommendations of international guidelines. The lower limit of quantification was 5.0pgmL(-1) for aliskiren and rivaroxaban and 0.5pgmL(-1) for prasugrel. The intra- and inter-day precision was within 7.12% and the accuracy ranged from -7.54% to 4.17%. The mean extraction recoveries of the MEPSC8 methodology were found to be 98.3% for aliskiren, 100.3% for rivaroxaban and 99.9% for prasugrel. This MEPSC8-UHPLC-MS/MS method offers a fast, simple and precise way to determine selected novel cardiac drugs in human urine that could be applied to therapeutic drug monitoring and pharmacokinetic studies.

Magiera S 《-》

Simultaneous quantification of enalapril and enalaprilat in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

Lu S ，Jiang K ，Qin F ，Lu X ，Li F ... -  《JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS》

Determination of aliskiren in human serum quantities by HPLC-tandem mass spectrometry appropriate for pediatric trials.

The orally active direct renin inhibitor aliskiren is approved for the treatment of essential hypertension in adults. Analytical methods utilized in clinical studies on efficacy and safety have not been fully described in the literature but need a large sample volume ranging from 200 to 700 μL, rendering them unsuitable particularly for pediatric applications. In the assay presented only 100 μL of serum is needed for mixed-mode solid-phase extraction. The chromatographic separation was performed on Xselect(TM) C18 CSH columns with mobile phase consisting of methanol-water-formic acid (75:25:0.005, v/v/v) and a flow rate of 0.4 mL/min. Running in positive electrospray ionization and multiple reaction monitoring the mass spectrometer was set to analyze precursor ion 552.2 m/z [M + H](+) to product ion 436.2 m/z during a total run time of 5 min. The method covers a linear calibration range of 0.146-1200 ng/mL. Intra-run and inter-run precisions were 0.4-7.2 and 0.6-12.9%. Mean recovery was at least 89%. Selectivity, accuracy and stability results comply with current European Medicines Agency and Food and Drug Administration guidelines. This successfully validated LC-MS/MS method with a wide linear calibration range requiring small serum amounts is suitable for pharmacokinetic investigations of aliskiren in pediatrics, adults and the elderly.

Burckhardt BB ，Ramusovic S ，Tins J ，Laeer S ... -  《-》