Validation of an Extended Metabolic Stability Assay Using Human Liver Subcellular Fractions

Authors

• M Kabir
• P Shah
• X Xu

Abstract

Drug metabolism, often referred to as biotransformation, occurs primarily in the liver and is considered as one of the major elimination pathways of xenobiotics from the body. Currently, the ADME/DMPK group at NCATS employ a single time-point assay for assessing in vitro metabolic stability for 60 mins. However, several drug discovery projects at NCATS require the evaluation of highly stable compounds in order to meet the project goal of selecting a drug candidate with long half-life (t1/2). To be able to rank compounds and select lead candidates for in vivo studies, longer incubation is required in the in vitro metabolic stability assays. Our goal is to assess whether these assays can be extended to test for compound stability beyond 60 mins. For this project, we measured the in vitro metabolic stability of 21 probe compounds in pooled human liver microsomes that were pre-incubated at 37°C for 60, 75, 90, 105 and 120 minutes. Similar experiments were done with 14 probe compounds in human cytosol fractions. The results showed consistent metabolic stability profile of the probe compounds even after 120 minutes of pre-incubation suggesting that the in vitro microsomal and cytosolic stability test can be extended up to 2 hours for better evaluation of highly stable compounds.

Scientific Focus Area: Molecular Pharmacology

This page was last updated on Friday, March 26, 2021