Microporous Volumetric Sampler to Enable Sampling and Storage of Blood in Dried State for Pharmaceutical Analysis

Blood collection from patients and its analysis for pharmacokinetics (PK), pharmacodynamics (PD) and therapeutic drug monitoring (TDM) is well established process hospitals and pharmaceutical industries. However, the challenge arises when blood need to be collected from a remote location, away from well-equipped laboratories, that lacks on-demand availability of paramedic staffs, necessary tools and required infrastructure like cold storage and transport. To circumvent the above problems, in the current work, we have developed a device for microsampling of blood in dried state. The device comprises of a fluid absorbing polyacrylamide cryogel matrix having a defined pore-size and porosity. It showed consistent blood sampling irrespective of hematocrit volume and facilitated quick drying. Further, these cryogels could draw $30 \mu \mathrm{l}$ of blood drops spiked with different concentration of drugs consistently. The cryogels having the dried blood were taken for the extraction of drugs through solvent phase extraction. Our results suggested that recovery of the drugs like caffeine and metronidazole from blood was comparable with the conventional method. Thus, our device could be potentially used for PK, PD and TDM studies overcoming the challenges of convention blood collection.