A review of recent advances in microsampling techniques of biological fluids for therapeutic drug monitoring
Tey & See
The finding, in our words
The review finds that volumetric absorptive microsampling addresses the haematocrit bias inherent in dried blood spots, making it suitable for therapeutic drug monitoring, but emphasises that each microsampling technique presents distinct analytical and logistical challenges that must be weighed for decentralised deployment.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
This narrative review evaluates microsampling devices for therapeutic drug monitoring, concluding that techniques such as volumetric absorptive microsampling and dried blood spots offer reliable, less invasive alternatives to venous sampling when paired with high-sensitivity mass spectrometry, which supports implementation in routine clinical practice.
In AML and CLL, 91% of VAMS venetoclax results fell within 20% of plasma after individualised haematocrit correction; in home sampling, 18 of 21 patients self-sampled independently and 76% of returned samples were analysable, which shows home microsampling is workable, though the authors ask for multicentre validation.
This review found that volumetric microsampling devices, such as Mitra, HemaPEN, HemaXis DB10, and Tasso-M20, overcome haematocrit bias, whilst Telimmune plasma separation cards enable direct plasma collection without centrifugation. These technologies support patient-centric, decentralised sampling, though the authors note that clinical validation remains limited across different drugs and patient populations.
The study validated an LC-MS/MS method for eight antiepileptic drugs and two metabolites in dried blood spot and VAMS formats, with satisfactory analytical performance and stability, and was the first to include the oxcarbazepine metabolite DHCB. In 80 paired patient samples, microsampling concentrations showed promising correlation with plasma, supporting decentralised therapeutic drug monitoring of antiepileptic treatment.
A UPLC-MS/MS method for linezolid and metabolites in oral fluid and VAMS capillary blood satisfied ICH M10 validation requirements. Linezolid concentrations correlated strongly with venous plasma in both matrices, offering a non‑invasive option for therapeutic drug monitoring, whereas metabolites were systematically underestimated in VAMS and seldom detectable in oral fluid, restricting metabolite measurement.