A Review of Blood-Based Microsampling Devices for Patient-Centered Application in Therapeutic Drug Monitoring

Background: Microsampling devices simplify the collection, transport, and storage of biological samples, thereby playing an important role in therapeutic drug monitoring (TDM). This review summarizes the current developments in blood-based microsampling devices, with a particular focus on their applicability in patient-centered settings. Methods: PubMed was searched for studies on blood-based microsampling devices and their suitability for patient-centered applications. Results: Dried blood spot sampling, the foundational technique for collecting small blood volumes, is limited by hematocrit-dependent variability. New volumetric technologies, such as Mitra volumetric absorptive microsampling, HemaPEN, HemaXis DB10, and Tasso-M20, address this issue and improve patient usability, enabling reliable self-sampling for TDM. Recent plasma separation cards, such as the Telimmune system, have further expanded plasma collection, enabling accurate bedside sampling of defined plasma volumes. This advancement holds significant promise for patient-centered applications because it eliminates the need for conversion between blood and plasma concentrations. Conclusions: Microsampling devices using capillary or volumetric technologies offer promising solutions for patient-centered TDM by enabling accurate and user-friendly home sampling. Among these, HemaXis DB10 and Tasso-M20 improved sampling consistency and ease of use, although clinical validation remains limited. Telimmune plasma separation cards enable direct plasma collection without centrifugation and eliminate the need for blood-to-plasma conversion, despite the limitations of small sample volumes. Overall, current developments demonstrate substantial potential for patient-centered TDM; however, further studies are required to evaluate device-specific suitability across different drugs and patient populations.