Liquid Chromatography-Based Approach Tested for Advancing Process Analytical Technology

Scientists from Roche Diagnostics GmbH in Penzberg, Germany tested a new liquid chromatography (LC)-based approach for advancing process analytical technology (PAT) in biopharmaceutical processing. Their findings were published in the Journal of Chromatography A (1).

Process analytical technology (PAT) is defined as a systematic approach to design, analyze and control manufacturing of (bio-)pharmaceuticals through establishing and monitoring Critical Process Parameters (CPP) in (or close to) real-time that affect Critical Quality Attributes (CQA) of the product. First outlined by the U.S. Food and Drug Administration (FDA) in 2004, this framework has also been incorporated in the International Council for Harmonization (ICH) guideline Q8 (R2). This is meant to ensure consistent product quality, and hence, patient safety. When applied to compliment a Quality by Design (QbD)-based approach, PAT can minimize the risk of batch failures, reduce the need for extensive offline testing, and improve the process, product understanding, and streamlined processes.

Applying PAT principles for manufacturing biotherapeutics proffers the prospect of ensuring consistent product quality, increased productivity, and substantial cost and time savings. This paradigm shift from a traditional, rather rigid manufacturing model to a more scientific, risk-based approach has been pushed for by health advocates for almost two decades; despite this, practical PAT implementation in the biopharmaceutical industry is still limited by a lack of fit-for-purpose analytical methods. While most proposed spectroscopic techniques are sufficiently fast, they exhibit deficiencies in selectivity and sensitivity. Well-established offline methods, such as ultrahigh-performance liquid chromatography (UHPLC), are too slow for this task.

In this study, the scientists introduced a novel online liquid chromatography (LC) setup specifically designed to enable real-time monitoring of critical product quality attributes during time-sensitive purification operations in downstream processing. Using this online LC solution in combination with fast, purpose-built analytical methods, sampling cycle times between 1.30 and 2.35 min were achieved, all without compromising the ability to resolve and quantify product variants of interest. Despite the shortened method run times, the results showed good comparability with corresponding reference materials.

This technique was tested in three different case studies, which involved various therapeutic modalities, downstream processing (DSP) unit operations, and analytical chromatographic separation modes. In this study, the versatility and utility of the pitched approach was demonstrated, showing process engineers a clear time advantage compared to analytical offline characterization of downstream process performance. In two of the three studies, the applied online measurements detected process-induced changes in the relative abundance of critical product attributes with high temporal resolution throughout the entire process. In contrast, the Protein A purification step of mAb-A was complemented by fraction collection and subsequent atline analysis to increase the sampling rate during the time-critical wash and elution steps. This is due to technical limitations closely linked with size-exclusion chromatography (SEC), which has relatively long run times despite recent advances in terms of column characteristics and extensive method optimization.

This study’s findings highlight the potential of online LC systems combined with (ultra-)fast chromatographic methods in helping as a PAT tool for monitoring product-related CQA during biopharmaceutical purification. According to the scientists, since LC-based methods are well-established in the (bio-)pharmaceutical industry, it can be assumed that this approach will be met with approval by health authorities.

References

(1) Graf, T.; Naumann, L.; Bonnington, L. et al. Expediting Online Liquid Chromatography for Real-Time Monitoring of Product Attributes to Advance Process Analytical Technology in Downstream Processing of Biopharmaceuticals. J. Chromatogr. A 2024, 1729, 465013. DOI: 10.1016/j.chroma.2024.465013