Competitiveness of Bioanalytical Laboratories— Technical and Regulatory Perspectives

摘要

The discovery and development of a new drug costs around $1 billion, and it may take approximately 10 years for the drug to reach the marketplace. Drug discovery and development are the processes of generating compounds and evaluating all of their properties to determine the feasibility of selecting one new chemical entity (NCE) to become a safe and efficacious drug. Among many criteria, obtaining experimental pharmacokinetics (PK) data from laboratory animals in the nonclinical stage is critical to evaluating a drug candidate before it can qualify to be tested in the clinical trials for safety and efficacy evaluation. A key parameter in pharmacokinetics is the plasma or tissue concentration of the new drug after its administration to laboratory animals. Therefore, developing an accurate and fast analytical method for measuring the concentrations of a compound in plasma or tissue is the first step toward yielding the PK of a compound. As the drug candidate moves down in the pipeline, the requirements for PK information differ at the different stages of drug discovery and development, leading to the introduction of “fit for purpose” analytical strategies that provide the appropriate level of bioanalytical support for the purpose at hand, while simultaneously minimizing resource expenditures. Due to its superior sensitivity and selectivity, liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) has become the analytical technique primarily used by bioanalytical laboratories performing analyses for preclinical and clinical studies. The increased number of biological agents used as therapeutics—in the form of recombinant proteins, monoclonal antibodies, vaccines, and so on—has prompted the pharmaceutical industry to review and refine aspects of the development and validation of bioanalytical methods for the quantification of these therapeutics in biological matrices in support of preclinical and clinical studies. Most of these methodologies are used in quantitative assays supporting PK and toxicokinetic parameters of the therapeutic agents. To date, an alternative approach for dealing with macromolecules is to utilize ligand-binding assays (LBAs) to generate data. LC–MS/MS has played an incredible role in drug metabolism and pharmacokinetics studies at various drug discovery and development stages since its introduction to the pharmaceutical and biotechnology industries. This paper will elaborate on the most recent advances in sample preparation and separation, along with the mass spectrometric aspects of high-throughput quantitative bioanalysis of drugs and metabolites in biological matrices. Recently introduced techniques such as ultra-performance or ultra-speed liquid chromatography (UPLC or USLC), with small particles (sub-2 mm) and monolithic chromatography, offer improvements in speed, resolution, and sensitivity compared to conventional chromatographic techniques. Hydrophilic interaction chromatography (HILIC) on silica columns with low aqueous/high organic mobile phase is emerging as a valuable supplement to the reversed-phase LC–MS/MS. Sample preparation formatted to 96-well and/or 384-well plates has allowed for semi-automation of off-line sample preparation techniques, significantly improving throughput. On-line solid phase extraction (SPE) utilizing column-switching techniques is rapidly gaining acceptance in bioanalytical applications to reduce both the time and labor required for generating bioanalytical results. Extraction sorbents for on-line SPE extend to an array of media, including large particles for turbulent-flow chromatography, restricted access materials, monolithic materials, and disposable cartridges utilizing traditional packings such as those used in Spark Holland (Symbiosis) systems. Bioanalytical laboratories in the pharmaceutical and life science industries are constantly under pressure to reduce overall time for discovery and development. This pressure is often accompanied by an incr