Accelerating Pharmaceutical Process Development with an Acoustic Droplet Ejection-Multiple Reaction Monitoring-Mass Spectrometry Workflow

Abstract

Fast-paced pharmaceutical process developments (e.g., high-throughput experimentation, directed evolution, and machine learning) involve the introduction of fast, sensitive, and accurate analytical assays using limited sample volumes. In recent years, acoustic droplet ejection (ADE) coupled with an open port interface has been invented as a sampling technology for mass spectrometry, providing high-throughput nanoliter analytical measurements directly from the standard microplates. Herein, we introduce an ADE-multiple reaction monitoring-mass spectrometry (ADE-MRM-MS) workflow to accelerate pharmaceutical process research and development (PR&D). This systematic workflow outlines the selection of MRM transitions and optimization of assay parameters in a data-driven manner using rapid measurements (1 sample/s). The synergy between ADE sampling and MRM analysis enables analytical assays with excellent sensitivity, selectivity, and speed for PR&D reaction screenings. This workflow was utilized to develop new ADE-MRM-MS assays guiding a variety of industrial processes, including (1) screening of Ni-based catalysts for C−N cross-coupling reaction at 1 Hz and (2) high-throughput regioisomer analysis-enabled enzyme library screening for peptide ligation reaction. ADE-MRM-MS assays were demonstrated to deliver accurate results that are comparable to conventional liquid chromatography (LC) experiments while providing >100-fold throughput enhancement.

Electrosynthesis of iminophosphoranes and applications in nickel catalysis

“…20 °C instead of >110 °C). 64 We explored the application of several iminophosphorane ligands (see ESI † for details) in the context of coupling aryl halide 61 with pyrrolidine (62) to access 63 ( Scheme 6D ) using electrochemical Ni-catalyzed conditions similar to those developed by Baran and coworkers. 65 Gratifyingly, we obtained site selective coupling (Br over the activated Cl) to product 63 in 62% yield (and less than 5% yield of the product associated with C–N coupling at the 2-chloro position was observed).…”

Continuous collective analysis of chemical reactions

“…To efficiently execute neutral loss analysis, we coupled it with rapid sampling via acoustic droplet ejection mass spectrometry (ADE-MS) 18,19 which allows direct introduction of nanoliter volumes into a mass spectrometer, eliminating any slow chromatographic steps (Extended Data Fig. 2b).…”

“…3a). We were able to leverage the fragmentation signatures associated with TIDA boronates (10)(11)(12)(13)(14)(15), Boc amines (16)(17)(18)(19)(20)(21), and THP alcohols (22)(23)(24)(25)(26)(27) to ascertain the relative product output of 384 chemical reactions in only 7.68 minutes each by NL-ADE-MS. This took an equivalent amount of time as collecting two LC-MS samples.…”

“…Encouraged by the performance of TIDA boronates in multiplexed analyses we re-visited our data for products derived from Boc amine 2 (16)(17)(18)(19)(20)(21) and THP alcohol 3 (22)(23)(24)(25)(26)(27) in a 6-plex format. In this multiplexed format we obtained reaction outcome data for 384 reactions in only 1.28 minutes.…”

“…A powerful aspect of these techniques are that common lost chemical pieces provide a direct means to select the desired analyte from amongst complex mixtures. Other advances in tandem mass spectrometry have increased the pace of reaction mixture analysis 11,18,19 however progress in this space has not yielded generalizable solutions because of the requirement of prior knowledge about analytes or the need for analytical standards.…”