Bioanalytical Assay Development and Validation: Reproducible and Reliable Quantitation of Analytes
Bioanalytical assay development helps determine the design implications, limitations, favorable conditions, and suitability of a drug for the intended treatment. Before assay development and validation can be initiated, it is recommended to understand the physiochemical properties of the analyte. Bioanalytical assay development is considerably informed by the details on protein binding and in vivo/in vitro metabolism along with essential aspects of prior work on the method. Bioanalytical assays play a crucial role in the discovery and development of pharmaceutical products given their ability to discern purity, identity, performance, and potency of these compounds. Furthermore, the involved techniques allow reproducible and reliable quantitation of analytes in various biological matrices, such as plasma, urine, blood, or serum.
Assay validation is performed for the analysis of drugs, metabolites, and biomarkers to ensure that the test results are precise and accurate, and the generated data is reasonably robust in supporting drug development and other intended purposes. Several method characteristics play a significant role during each stage of assay development and validation, including specific chemistry of analyte, sample clean-up to analysis methodology, and desired method sensitivity. The selectivity and sensitivity of bioanalytical assays developed for drug and metabolite quantitation thoroughly impact the success of preclinical and clinical studies. Thus, careful sample preparation, HPLC column, and mobile phase selection, and choice of detector and quantitation method are critical during LC-MS assay development.
The purpose of assay development and validation is to find a suitable method applicable to a chosen analyte in a specific biological matrix. The analysis outcome might be inaccurate if the assay is not validated correctly and deemed unreliable. This assay inadequacy could be due to low sensitivity, selectivity, precision, accuracy or any other reason. Given the significance of this topic, the FDA has published guidance to provide guardrails around assay development and validation discussions. Generally, the assay can be used with full confidence to produce reliable data if the FDA method development guidance is followed and all its outlined criteria are met. Thus, assay development and validation are carried out with appropriate technology so that compliance with regulatory and scientific requirements can be achieved. Additionally, analytical information obtained from already existing bioanalytical assays may sometimes be effectively utilized.
Assay Development and Validation: From Drug Discovery and Preclinical to Clinical Phases
During preclinical development, bioanalytical assays assess the impact of New chemical entity (NCE) as a potential treatment on various animal species. Further assay development and validation is required to evaluate pharmacokinetic parameters, toxicity, and safety profile in humans of the drug compound that reaches the clinical stage. Sample collection, processing, and preparation should be thoroughly assessed before starting assay development to mitigate future risk factors at a later stage and validation phase.
Simply put, bioanalytical assays are imperative in improving a drug candidate’s success rate in preclinical animal studies. Robust assay development and validation during early preclinical studies is time well spent as satisfactory assays can be carried out further into development stages with minimal effort. Bioanalytical assays during clinical studies in human volunteers involve quantitation of analytes and corresponding metabolites as well as an assessment of various matrices. This analysis provides significant guidance on toxicokinetic and pharmacokinetic parameters evaluated through assay development and validation.
