Simple Strategies for Reducing Sample Loads in In Vitro Metabolic Stability High-Throughput Screening Experiments: A Comparison between Traditional, Two-Time-Point and Pooled Sample Analyses

Abstract Higher‐throughput ADME programs in early drug discovery are becoming common throughout the pharmaceutical industry as companies strive to reduce their compound attrition in later‐stage development. Many of the ADME assays developed into higher‐throughput formats rely on LC/MS analyses. Since the biological aspects of the assay are amenable to parallel processes using dense plate formats, the number of samples generated from these assays produce a large analysis load for serial LC/MS. Presented in this report are two novel strategies, including a sample pooling method and a two time‐point method, that could be used in drug discovery to reduce the number of samples generated during multiple time‐point in‐vitro ADME assays. One hundred and sixty‐three compounds were subjected to human microsomal incubations with full time‐point method samples taken at t = 0, 5, 15, 30, and 45 min. The ER data correlation (R 2 ) between the full time‐point method and the pooling method and two time‐point methods were 0.98 and 0.97, respectively. Both methods have the potential to: 1. produce data of similar quality to traditional high throughput ADME assays, 2. be easily implemented, 3. shorten analytical run times, and 4. be reproducible and robust. © 2004 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:38–45, 2005