The Use of Surrogate Matrix for Calibrators in the Analysis of Dried Blood Samples - A Feasibility Study

Experiments designed to assess the ability to analyze Volumetric Absorptive Microsampling (VAMS^®) or Tasso-M20 dried blood samples using ligand binding assays to support pharmacokinetic studies are described. An internally developed monoclonal antibody therapeutic A (mAb A) was employed as a model compound to facilitate this evaluation. The challenges of daily preparation of VAMS^® calibrators in wet blood and the identification of a suitable diluent for use with dried blood samples at high analyte concentrations were addressed. A suitable surrogate matrix solution was identified for constructing calibrators, enabling accurate quantitation from dried blood samples. Additionally, utilizing surrogate matrix solutions as a diluent confirmed the absence of bias in the quantitation of diluted samples. The results of this feasibility study demonstrate the potential of using a surrogate matrix solution to address challenges associated with the analysis of dried blood samples via ligand binding methodology.