A novel relay method for determining low-clearance values

Drug Metab Dispos. 2012 Sep;40(9):1860-5. doi: 10.1124/dmd.112.046425. Epub 2012 May 29.

Abstract

A novel relay method has been developed using cryopreserved human hepatocytes to measure intrinsic clearance of low-clearance compounds. The relay method involved transferring the supernatant from hepatocyte incubations to freshly thawed hepatocytes at the end of the 4-h incubation to prolong the exposure time to active enzymes in hepatocytes. An accumulative incubation time of 20 h or longer in hepatoctyes can be achieved using the method. The relay method was validated using seven commercial drugs (diazepam, disopyramide, theophylline, timolol, tolbutamide, S-warfarin, and zolmitriptan) that were metabolized by various cytochrome P450s with low human in vivo intrinsic clearance at approximately 2 to 15 ml · min⁻¹ · kg⁻¹. The results showed that the relay method produced excellent predictions of human in vivo clearance. The difference between in vitro and in vivo intrinsic clearance was within 2-fold for most compounds, which is similar to the standard prediction accuracy for moderate to high clearance compounds using hepatocytes. The relay method is a straightforward, relatively low cost, and easy-to-use new tool to address the challenges of low clearance in drug discovery and development.

MeSH terms

  • Biological Assay* / methods
  • Biotransformation
  • Cell Fractionation* / methods
  • Cells, Cultured
  • Cryopreservation
  • Cytochrome P-450 Enzyme System / metabolism*
  • Hepatocytes / enzymology*
  • Humans
  • Kinetics
  • Metabolic Clearance Rate
  • Models, Biological
  • Pharmaceutical Preparations / metabolism*
  • Reproducibility of Results
  • Subcellular Fractions / enzymology

Substances

  • Pharmaceutical Preparations
  • Cytochrome P-450 Enzyme System