ABSTRACT
Assay Use References
Regulatory An analytical procedure used to evaluate a de€ned characteristic of the drug substance or drug product. This is a legally recognized procedure for the purpose of measuring a compendial item. A regulatory analytical procedure usually uses an International Reference Standard. Regulatory analytical procedures are in the manufacturing of cGMP products and may include assays for identi€cation, quantitative tests for the active pharmaceutical ingredient, and impurities
20, 21
Alternative analytical procedure
A validated assay that can be used in the absence of a regulatory assay (usually used when a regulatory analytical procedure is not available)
Stability-indicating assays An assay used to demonstrate the stability of a biopharmaceutical. These assays are used to demonstrate the stability of a biopharmaceutical during development
Bioanalytical assay An assay that measures a biomarker (analyte) within a biological matrix such as blood or urine
24-27
Chemical assay An assay that is considered more chemical than biological in nature. Such assays include assays for electrolytes and metabolites like glucose. Colorimetric assays for protein and carbohydrate are chemical assays. Classical drugs (as opposed to biopharmaceuticals) are usually (but not alwaysa) measured with chemical assays
Microbiological or ligand binding assay
These assays are biological assays and this category would also include cell-based assays other than microbiological assays. Examples include immunological assays such as ELISA assays and multiplex assays. In general, biological assays are more complex (and expensive) than chemical assaysb
a The development of high-throughput immunological assays has proved useful for the assay of drugs. SeeKraemer,T.andPaul,L.D.,Bioanalyticalproceduresfordeterminationofdrugsofabuseinblood, Anal. Bioanal. Chem. 388, 1415-1435, 2007.
