Determination of drug exposure levels in intestinal mucosa by quantitative UHPLC/TOFMS

摘要

1. The ability to predict in vivo oral absorption based on ex vivo screening is a critical component for rapid assessment of potential drug substances prior to formulation and clinical trials. Future experiments will be directed towards establishing the relationship between the exposure levels found in tissue, the rate of ex vivo transport and the pharmacological endpoint being investigated. The generation of this relationship requires a robust analytical method to generate data on compounds of both similar and structurally diverse classes of molecules such as been described utilizing quantitative UHPLC/TOFMS. 2. Ease of use for UHPLC/TOFMS as a quantitative tool (1) A single acquisition method can be utilized for a series of analytes that ionize by a similar mechanism (e.g., positive ESI); (2) Narrow width EIC's calculated from the molecular formula specific for each monoisotopic m/z may be extracted from the full scan array data set to provide selective detection; (3) Trap-pulse enhancement to optimize duty cycle (in this case, 10X increase in signal at m/z 550) with a reduced mass acquisition range (e.g., m/z 300-700) to manage data file size can be performed from initial instrument calibration (m/z 100-1000) just by utilizing a 2-point lock mass correction (4) Although instrument response may vary over the course of a long sequence, updating the standard curve every couple of hours will allow for a quantitation method with an external calibration.