Reactor design and selection for effective continuous manufacturing of pharmaceuticals.

Pharmaceutical production remains one of the last industries that predominantly uses batch processes, which are inefficient and can cause drug shortages due to the long lead times or quality defects. Consequently, pharmaceutical companies are transitioning away from outdated batch lines, in large part motivated by the many advantages of continuous manufacturing (e.g., low cost, quality assurance, shortened lead time). As chemical reactions are fundamental to any drug production process, the selection of reactor and its design are critical to enhanced performance such as improved selectivity and yield. In this article, relevant theories, and models, as well as their required input data are summarized to assist the reader in these tasks, focusing on continuous reactions. Selected examples that describe the application of plug flow reactors (PFRs) and continuous-stirred tank reactors (CSTRs)-in-series within the pharmaceutical industry are provided. Process analytical technologies (PATs), which are important tools that provide real-time in-line continuous monitoring of reactions, are recommended to be considered during the reactor design process (e.g., port design for the PAT probe). Finally, other important points, such as density change caused by thermal expansion or solid precipitation, clogging/fouling, and scaling-up, are discussed.

An automated modular assembly line for drugs in a miniaturized plant.

We report here a fully automated, end-to-end, integrated continuous manufacturing process for a small-molecule generic medication with built-in quality assurance. The entire process fits into a box of 30.7 m2 modular footprint and a total residence time of less than 30 h, with a throughput up to 40.3 × 106 tablets per year.

Microfluidic investigation of the deposition of asphaltenes in porous media.

The deposition of asphaltenes in porous media, an important problem in science and macromolecular engineering, was for the first time investigated in a transparent packed-bed microreactor (µPBR) with online analytics to generate high-throughput information. Residence time distributions of the µPBR before and after loading with ~29 µm quartz particles were measured using inline UV-Vis spectroscopy. Stable packings of quartz particles with porosity of ~40% and permeability of ~500 mD were obtained. The presence of the packing materials reduced dispersion under the same velocity via estimation of dispersion coefficients and the Bodenstein number. Reynolds number was observed to influence the asphaltene deposition mechanism. For larger Reynolds numbers, mechanical entrapment likely resulted in significant pressure drops for less pore volumes injected and less mass of asphaltenes being retained under the same maximum dimensionless pressure drop. The innovation of packed-bed microfluidics for investigations on asphaltene deposition mechanisms could contribute to society by bridging macromolecular science with microsystems.