Additive Manufacturing a One-Piece Microfluidic Device Coupled to Liquid Chromatography–Mass Spectrometry for In Vitro Drug Metabolism Analysis

Abstract Understanding the metabolism of drugs is a principal consideration when it comes to understanding the activity of a precursor drug and determining if the precursor is converted into bioactive metabolites after ingestion in the human body. This process is typically studied using either animal models or in vitro models, such as human liver microsomes (HLM). In this research, a novel one-piece microreactor was fabricated with light-curing 3D printing technology, which can be seamlessly and directly integrated with a liquid chromatography–mass spectrometer (LC–MS) system for drug metabolic analysis after an in vitro human liver microsomal reaction. The results clearly showed that: (1) this system was able to conduct metabolic reactions (demonstrated by three commonly abused substances or impurity in illicit heroin including heroin, 6-acetylcodeine, and buprenorphine) at the operation temperature of 37 °C and operation pressure ranging from 7.8 to 21.5 bars, and its performance was very competitive to the conventional method while reducing total processing steps and minimizing manual operation, (2) the integrated LC–MS system demonstrated a high stability and precision where the RSD of chromatographic peak area and retention time was only 2.53% and 0.91%, and (3) the 3D printed reactors, featuring an integrated locking design and a bonded filtration membrane, can significantly enhance usage convenience, reduce specimen process time, and resist high back pressure, potentially advancing drug metabolism studies.