Microscale HPLC Predicts Preparative Performance at Millionfold Scale

Introducing Multifactorial Peak Crossover in Analytical and Preparative Chromatography via Computer-Assisted Modeling

Modern pharmaceutical processes can often lead to multicomponent mixtures of closely related species that are difficult to resolve under chromatographic conditions, and even worse in preparative scale settings. Despite recent improvements in column technology and instrumentation, there remains an urgent need for creating innovative approaches that address challenging coelutions of critical pair and poor chromatographic productivity of purification methods. Herein, we overcome these challenges by introducing a simple and practical technique named multifactorial peak crossover (MPC) via computer-assisted chromatographic modeling. The approach outlined here focuses on mapping the separation landscape of pharmaceutical mixtures to quickly identify spaces of peak coelution crossings which enables one to conveniently switch the elution order of target analytes. Diverse examples of MPC diagrams as a function of column temperature, mobile phase gradient or a multifactorial combination in reversed phase and ion exchange chromatography (RPLC and IEC) modes are generated using ACD Laboratories/LC Simulator software and corroborated with experimental data match (overall retention time differences of less than 1%). This powerful MPC technique allows us to gain massive productivity increases (shorter cycle time and higher sample loading) for purification of pharmaceuticals by selectively switching the elution order of target components away from undesired tailing peaks and coelution spaces. MPC chromatography dramatically reduces the time spent developing productive analytical and preparative scale separations. In addition, we illustrate how this new MPC concept can be used to gain substantial improvements of the signal-to-noise ratio, enabling straightforward ppb detection of low-level target components with direct impact in the quantitation of metabolites and potential genotoxic impurities (PGIs). These innovations are of paramount importance in order to facilitate efficient isolation, characterization, and quantitation of drug substances in the development of new medicines.

Enhanced fluidity liquid chromatography: A guide to scaling up from analytical to preparative separations

The evolution of supercritical fluid chromatography (SFC) instrumentation, improved detection capability, and expanded modifier range has led to extending the reach of SFC to the analysis of a broader spectrum of analytes beyond enantioselective separations. However, preparative SFC has yet to see the same technological revitalization, especially in regards to the purification of highly polar analytes. Enhanced fluidity liquid chromatography (EFLC) has been demonstrated as one of the ways to extend the applicable range of SFC instrumentation to highly polar analytes such as proteins, carbohydrates, and nucleotides. Despite recent applications of EFLC for challenging mixtures of hydrophilic metabolites and analogs, its viability in preparative purification, which is of great importance to the pharmaceutical industry, remains unknown. Herein, multiple chromatographic parameters that are critical to achieve feasible EFLC purification methods were investigated, including system pressure as a function of modifier composition (for several MeOH:H₂O ratios), effect of diluent injection conditions on peak shape, and optimization of mass load with diluent composition. The usage of 50% acetonitrile or methanol diluents provided the most volumetric loading capacity. In the case of sucrose, leveraging higher analyte solubility in water proved to be more favorable than the volumetric loading capacity of diluents with higher organic content. In fact, an 80 mg injection of sucrose was possible on a 2 cm preparative HILIC column with minimal peak shape degradation. The combined information led to the successful demonstration of EFLC for the preparative separation of sugars using readily available MS-directed SFC instrumentation.

High throughput analysis enables high throughput experimentation in pharmaceutical process research

High throughput experimentation has become widely used in the discovery and development of new medicines.

The locks and keys to industrial biotechnology

The sustainable use of resources by Nature to synthesize the required products at the right place, when they are needed, continues to be the role model for total synthesis and production in general. The combination of molecular and engineering science and technology in the biotechnological approach needs no protecting groups at all and has therefore been established for numerous large-scale routes to both natural and synthetic products in industry. The use of biobased raw materials for chemical synthesis, and the economy of molecular transformations like atom economy and step economy are of growing importance. As safety, health and environmental issues are key drivers for process improvements in the chemical industry, the development of biocatalytic reactions or pathways replacing hazardous reagents is a major focus. The integration of the biocatalytic reaction and downstream processing with product isolation has led to a variety of in situ product recovery techniques and has found numerous successful applications. With the growing collection of biocatalytic reactions, the retrosynthetic thinking can be applied to biocatalysis as well. The introduction of biocatalytic reactions is uniquely suited to cost reductions and higher quality products, as well as to more sustainable processes. The transfer of Nature's simple and robust sensing and control principles as well as its reaction and separation organization into useful technical systems can be applied to different fermentations, biotransformations and downstream processes. Biocatalyst and pathway discovery and development is the key towards new synthetic transformations in industrial biotechnology.