Characterization of matrix effects in developing rugged high-throughput LC-MS/MS methods for bioanalysis

Simultaneous quantitation of befotertinib (D-0316) and its metabolite D-0865 in human plasma by LC-MS/MS method

A sensitive and reliable method was developed to determine befotertinib (D-0316) and its metabolite D-0865 from human plasma by LC-MS/MS. The samples were prepared by simple protein precipitation and 2 µL of the supernatant were chromatographed on a C18 analytical column (ACE Excel 2 Super C₁₈, 50 × 2.1 mm). Elution was performed with mobile phase A (10 mM ammonium acetate in water containing 1 % formic acid) and mobile phase B (acetonitrile containing 1 % formic acid) under a gradient program in a total run time of 4 min. Triple Quadruple 5500 equipped with Turbo Ion Spray source and multiple reaction monitoring (MRM) were used for the analysis detection. The transitions were m/z 568.3 → 72.1 m/z (befotertinib), m/z 554.2 → 497.2 (D-0865), and m/z 455.2 → 164.9 (verapamil, internal standard). According to the Chinese Pharmacopeia Commission and ICH Harmonised Guideline for Bioanalytical Method Validation, this method was validated within the spectrum of its accuracy, precision, selectivity, linearity, recovery, matrix effect, and stability. This LC-MS/MS method was successfully applied for the quantitation of befotertinib and its metabolite D-0865 in human plasma during the pharmacokinetics study of befotertinib in non-small cell lung cancer (NSCLC) patients.

Tracing the anticancer compound [RuII(η6-p-cymene)(8-oxyquinolinato)Cl] in a biological environment by mass spectrometric methods

Ruthenium-based complexes have attracted attention as promising anticancer candidates due to their lower general toxicity than the widely used platinum drugs. The complex [Ru^II(η⁶-p-cymene)(8-oxyquinolinato)Cl] 1 has shown significant cytotoxic activity in cancer cells, independent of the cellular uptake. In an attempt to rationalize this finding, we investigated the fate of 1 in cells as well as developed an analysis method for 1 and its derivatives based on molecular mass spectrometry. The methods were applied for the analysis of cell medium and HCT116 human colorectal cancer cell lysate samples. The amount of Ru detected in cell lysate after treatment with 1 by ICP-MS was virtually time-independent, while the Ru content in the cell pellet increased significantly over the course of 24 h. The compound was still detectable by LC-ESI-TOF-MS after 24 h in cell lysate as its [1- Cl]⁺ ion that may be formed directly from 1 or after a chlorido-aqua ligand exchange reaction facilitated in the cytosol.

Sensitive LC–MS/MS method for quantitation of levodopa and carbidopa in plasma: application to a pharmacokinetic study

Aim: The combination of levodopa with carbidopa has been used for treatment of Parkinson's disease being an important therapy in dopamine level control in the brain. Both are very polar compounds becoming a challenge for analysis by LC–MS/MS.Materials & methods: In this work, it was developed and validated a sensitive bioanalytical method by UHPLC–MS/MS for simultaneous levodopa and carbidopa quantification in human plasma using a fast protein precipitation method. Moreover, the bioanalytical method was applied to a pharmacokinetic study in healthy volunteers. Results/Conclusion: The results demonstrated a sensitive and adequate method for application to pharmacokinetic/bioequivalence studies.

Current antiviral drugs and their analysis in biological materials - Part II: Antivirals against hepatitis and HIV viruses

This review is a Part II of the series aiming to provide comprehensive overview of currently used antiviral drugs and to show modern approaches to their analysis. While in the Part I antivirals against herpes viruses and antivirals against respiratory viruses were addressed, this part concerns antivirals against hepatitis viruses (B and C) and human immunodeficiency virus (HIV). Many novel antivirals against hepatitis C virus (HCV) and HIV have been introduced into the clinical practice over the last decade. The recent broadening portfolio of these groups of antivirals is reflected in increasing number of developed analytical methods required to meet the needs of clinical terrain. Part II summarizes the mechanisms of action of antivirals against hepatitis B virus (HBV), HCV, and HIV, their use in clinical practice, and analytical methods for individual classes. It also provides expert opinion on state of art in the field of bioanalysis of these drugs. Analytical methods reflect novelty of these chemical structures and use by far the most current approaches, such as simple and high-throughput sample preparation and fast separation, often by means of UHPLC-MS/MS. Proper method validation based on requirements of bioanalytical guidelines is an inherent part of the developed methods.