Bioanalytical Assays - Toxicokinetics

When a macromolecule moves into development, early toxicokinetic (TK) protocols (e.g., dose range finding) and ADME studies will require bioanalytical assay support. At this time, better characterized reference standard should be available, along with more mature critical reagents. The assay developer continues to gain knowledge of the assay performance by continuing characterization studies and... 

Given the foregoing discussion of some of the unique characteristics of macromolecules that lead to clear differences in their pharmacokinetics compared to those typical of small-molecule drugs, there is a subset of the entire group of bioanalytical assay validation parameters that are of key importance in support of pharmacokinetics of candidate macromolecular therapeutics. Assuming demonstration of accuracy and precision of sufficient quality for the intended application of the assay (e.g., non-GLP discovery support or GLP toxicokinetic support, as discussed above), the most important characteristics of a given assay in support of pharmacokinetic studies are likely to be selectivity, specificity, and reproducibility for analysis of incurred samples. These are all related to the ability of the LBA to detect and quantitate solely, or as closely as possible to solely, the analyte of interest. 

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