Therapeutic Drug Monitoring of COVID-19 Drugs with Components of a Commercial Assay
Researchers are working furiously to test a variety of potential drugs to find a suitable treatment for COVID-19, the disease caused by SARS-CoV-2. Dose tolerance and dose response exploration studies are usually required that demands for a great analysis. Pharmacokinetic and pharmacodynamic studies are also often involved in these phases. But also later,should one of the drugs be approved, TDM may be a requirement. To help laboratories with this challenge, we describe a protocol* that allows the determination of 9 COVID-19 drug candidates and metabolites in a short run time on the basis of MassTox® TDM Series A*, a modular system that allows the determination of more than 200 drugs.
(active metabolite of Remdesivir)
Table 1: The Drugs of COVID-19 Calibrator
Materials and Methods
The sample preparation was performed in line with the MassTox Series A protocol (Chromsystems). In brief: 50 μl of sample, reconstituted 3PLUS1® calibrator (order. No 92055) or MassCheck® control (order. no. 0268, 0269), containing 9 drugs and metabolites (see table 1), was pipetted into a 1.5 ml reaction vial. 25 μl of Extraction Buffer (order. no 92005) was added and briefl y mixed. 250 μl of a mixture (Internal Standard Mix Anti-HIV drugs, order no. 92844, and Precipitation Reagent, order no. 92012, at a 1:16 ratio), was added and vortexed for 30 s and centrifuged for 5 min at 15000 g. The supernatant was then diluted, depending on sensitivity of the LC-MS/MS-system, with Dilution Buffer 1 (92007; ratio 1:5) or Dilution Buffer 2 (92008; ratio 1:20). The substances were separated on MasterColumn A® (order no. 92110) according to the protocol below and detected with electrospray ionisation in positive ion mode with a Sciex 6500 Citrine mass spectrometer. MRM transitions and internal standard assignments are found in table 3.
Injection volume: 10-20 µl
Column and autosampler temperature: ambient
Flow rate: 0.6 ml/min
Column: MasterColumn® A (order. no 92110)
Analysis time: 3.5 min