2025 · Journal of chromatography. B, Analytical technologies in the biomedical and life sciences · paywalled
Analytical and clinical validation of a volumetric absorptive microsampling (VAMS) - Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the analysis of Clofazimine in whole blood
Nugraha et al.
The finding, in our words
VAMS finger-prick sampling showed moderate agreement with conventional venous sampling for clofazimine, with a systematic 13% lower concentration that can be corrected, and was more cost-effective by about 4.45 USD per sample, supporting its use for routine therapeutic drug monitoring in MDR-TB.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Volumetric absorptive microsampling of whole blood did not provide a reliable basis for calculating meropenem plasma concentrations in critically ill children, so a validated low volume plasma method was required for paediatric therapeutic drug monitoring.
Clinical validation for tacrolimus and mycophenolic acid monitoring showed that while volumetric absorptive microsampling met analytical criteria after concentration correction, conventional dried blood spots achieved superior adherence to strict clinical criteria, sample quality, and cost efficiency without significant haematocrit bias.
The validated LC-MS/MS method showed similar pharmacokinetic profiles for albendazole and its metabolites across plasma, whole blood, dried blood spots and Mitra microsamples from hookworm-infected adolescents, supporting microsampling for paediatric pharmacokinetic studies. Mitra extraction proved more robust than dried blood spots during validation and is recommended for future albendazole pharmacokinetic work, despite higher albendazole sulfone concentrations observed in both microsampling devices compared with wet matrices.
In lung and renal transplant recipients, VAMS sampling with LC-MS/MS quantification of mycophenolic acid and tacrolimus showed good linearity and accuracy, and with a haematocrit-adjusted conversion formula achieved clinical agreement in most samples; tacrolimus did not require haematocrit correction. The approach is virtually painless and enables richer sampling for more accurate drug exposure estimates, supporting decentralised therapeutic drug monitoring.
An LC-MS/MS method for tamoxifen and six metabolites in VAMS was developed and validated, with water prerinsing improving recoveries and poor room temperature stability but stability for at least 100 days at minus 80 degrees Celsius. Plasma to blood ratios were used to estimate plasma equivalent concentrations, and paired VAMS and plasma samples from ten breast cancer patients showed strong correlations and good agreement on Bland-Altman analysis, supporting reliable decentralised TDM.