Bioanalytical applications metabolite

In other bioanalytical applications, the emphasis lies more on overcoming cross-reactivity. For example, the heart glycoside digoxin is cross-reactive with several of its metabolites as well as with plasma constituents, thus hampering approaches solely based on immunoassays. By treating plasma samples with sohd-phase extraction on a restricted access column, coupled online to reversed-phase LC/immunodetection, digoxin and two of its cross-reactive metabolites were analyzed in patients treated with the heart glycoside. 

As for any bioanalytical method, the extent of validation for an immunoassay should be related to the intended application of the assay. Thus, if an immunoassay is intended to support rapid screening in discovery R D, the characterization of specificity and the accuracy and precision specifications may be less stringent than if the assay is used to support pre-clinical and clinical development studies. Indeed, an assay for discovery support may be designed to detect active metabolites as well as parent molecule, so that... 

In Conference Report II, selectivity was defined as follows Selectivity is the ability of the bioanalytical method to measure unequivocally and to differentiate the analyte(s) in the presence of components, which may be expected to be present . Typically, these might include metabolites, impurities, degradants, matrix components, etc. [10]. This definition is very similar to the one established by the ICH [13], but takes into account the possible presence of metabolites, and thus is more applicable for bioanalytical methods. 

For pharmaceutical applications, the term bioanalysis refers to quantitative determination of a drug or its metabolites in a biological matrix. Although this term has traditionally been used to describe the analysis of in vivo samples (i.e., plasma or serum), current use of the term encompasses a broader range of applications that include the analysis of in vitro samples. Under this broader dehnihon, possible bioanalytical sample types can range anywhere from transport media to tissue homogenate. 

SucKOW, R. F., and Cooper, T. B., 1980, The electrochemical detection of imipramine, desipramine, and their 2-hydroxylated metabolites in plasma using reversed-phase paired-ion liquid chromatography. First International Symposium on Neurochemical and Clinical Applications of LCEC, Indianapolis, Abstract No. 8, Bioanalytical Systems, West Lafayette, Indiana. 

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