Determination of the antiretroviral drug tenofovir in plasma from HIV‐infected adults by ultrafast isotope dilution MALDI‐triple quadrupole tandem mass spectrometry

Abstract

A new and reliable mass spectrometric method using an isotope dilution method in combination with matrix-assisted laser desorption/ionization-triple quadrupole tandem mass spectrometry (ID-MALDI-QqQ-MS/MS) has been developed and validated for the determination of concentrations of the antiretroviral drug tenofovir (TNV) in plasma from HIV-infected adults. The advantage of this new method is that (1) the method is ultrafast and (2) can be applied for high-throughput measurement of TNV in plasma. The method is based on a simple plasma deproteinization step in combination with the use of [adenine-(13) C(5) ]-TNV as the internal standard. TNV and [adenine-(13) C(5) ]-TNV were monitored by multiple reaction monitoring using the transition m/z 288.0 → 176.2 and m/z 293.2 → 181.2 for TNV and [adenine-(13) C(5) ]-TNV, respectively. The method was validated according to the most recent FDA guidelines for the development and validation of (new) bio-analytical assays. Validated method parameters were: linearity, accuracy, precision and stability of the method. The lowest limit of quantification was 0.10 µmol/l, whereas the limit of detection determined at a signal-to-noise ratio (S/N = 3:1) in pooled drug free human control plasma was 0.04 µmol/l. The validated method was successfully applied and tested for its clinical feasibility by the analysis of plasma samples from selected HIV-infected adults receiving the prodrug tenofovir disoproxil fumarate. Observed plasma TNV concentrations ranged between 0.11 and 0.76 µmol/l and measured plasma TNV concentrations were within the therapeutically relevant concentration range.

Simultaneous determination of lamivudine, lopinavir, ritonavir, and zidovudine concentration in plasma of HIV‐infected patients by HPLC‐MS/MS

“…Although a number of analytical methods have been developed for anti-HIV drugs determination in human plasma (4,10,(16)(17)(18)(19)(20)(21)(22)(23)(24), the HPLC-MS/MS method here reported, using a QqTOF mass analyzer, displays great advantages including the possibility to obtain very high specificity towards the selected analytes (e.g., the anti-HIV drugs considered), despite a simple and rapid sample preparation. This target was achieved by the rational exploitation of the chromatographic and mass-spectrometric tools.…”

Antiretroviral Pharmacology in Mucosal Tissues

“…54,55 MALDI has been used previously to quantify ARVs in plasma and represents a promising approach to understanding drug disposition in tissues. 56 …”

Synthesis of 18O-labeled RNA for application to kinetic studies and imaging

“…Isotope dilution mass spectrometry has previously been used for the quantification of a therapeutic monoclonal antibody containing 13 C and 15 N (29) and an antiretroviral drug containing 13 C (30), with the isotopically labeled compound as the internal standard in both studies. However, it is difficult to apply such isotopic-labeling methods to the analysis of large molecules such as proteins and oligonucleotides because the mass difference between the unlabeled compound and the isotopically labeled compound cannot be reliably determined without additional treatment such as enzymatic digestion or fragmentation (6,29).…”