title: High-throughput metabolic stability studies in drug discovery by orthogonal acceleration time-of-flight (OATOF) with analogue-to-digital signal capture (ADC).
abstract: Screening assays capable of performing quantitative analysis on hundreds of compounds per week are used to measure metabolic stability during early drug discovery. Modern orthogonal acceleration time-of-flight (OATOF) mass spectrometers equipped with analogue-to-digital signal capture (ADC) now offer performance levels suitable for many applications normally supported by triple quadruple instruments operated in multiple reaction monitoring (MRM) mode. Herein the merits of MRM and OATOF with ADC detection are compared for more than 1000 compounds screened in rat and/or cryopreserved human hepatocytes over a period of 3 months. Statistical comparison of a structurally diverse subset indicated good agreement for the two detection methods. The overall success rate was higher using OATOF detection and data acquisition time was reduced by around 20%. Targeted metabolites of diazepam were detected in samples from a CLint determination performed at 1 microM. Data acquisition by positive and negative ion mode switching can be achieved on high-performance liquid chromatography (HPLC) peak widths as narrow as 0.2 min (at base), thus enabling a more comprehensive first pass analysis with fast HPLC gradients. Unfortunately, most existing OATOF instruments lack the software tools necessary to rapidly convert the huge amounts of raw data into quantified results. Software with functionality similar to open access triple quadrupole systems is needed for OATOF to truly compete in a high-throughput screening environment.
authors.affiliation: Discovery Drug Metabolism and Pharmacokinetics Department, Astrazeneca, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK. Dave.Temesi@AstraZeneca.com
authors.forename: David G
authors.initials: DG
authors.lastname: Temesi
authors.forename: Scott
authors.initials: S
authors.lastname: Martin
authors.forename: Robin
authors.initials: R
authors.lastname: Smith
authors.forename: Christopher
authors.initials: C
authors.lastname: Jones
authors.forename: Brian
authors.initials: B
authors.lastname: Middleton
mesh_terms: D000818:Animals; D055808:Drug Discovery; D004355:Drug Stability; D022781:Hepatocytes / Q000737:chemistry / Q000378:metabolism; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004364:Pharmaceutical Preparations