ISC 2026 Update: (Bio)pharmaceuticals

A morning session on Wednesday, September 9, 2026, at ISC 2026 in Prague, Czech Republic, focused on innovations in (bio)pharmaceutical analysis and was moderated by Frederic Lynen from Ghent University, Belgium, and Hailin Wang from the Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, China.^1,2

Davy Guillarme from the University of Geneva, School of Pharmaceutical Sciences, Switzerland, opened the session with Next-Generation Chromatographic Approaches for Oligonucleotide Analysis, an overview of recent chromatographic strategies for analyzing therapeutic oligonucleotides, whose growing structural complexity and size place particular demands on selectivity, efficiency, and detection, according to Guillarme. Their large molecular size, chemical modifications, and closely related impurities often limit the performance of conventional reversed-phase liquid chromatography (RPLC). Although ion-pairing RPLC (IP-RPLC) remains the reference approach, alternative chromatographic strategies are gaining interest.

Hydrophilic interaction liquid chromatography (HILIC) was investigated by his team using a targeted design-of-experiments (DoE) strategy, leading to a descriptor-based model of ON retention. The model highlighted the contributions of hydrogen bonding, dipole–dipole, solvophobic, and ionic interactions, providing a more rational basis for HILIC method development.

Pressure-enhanced liquid chromatography (PE-LC) was also investigated and revealed distinct behavior between chromatographic modes. Guillarme reported that increasing pressure enhanced retention in IP-RPLC but reduced retention in HILIC, demonstrating their different underlying mechanisms.

Several less-established approaches, including phenyl-based RPLC, size-exclusion chromatography (SEC), and bridging ion separation technique (BIST), were also evaluated. Additionally, an automated IP-RPLC screening platform was developed to systematically assess stationary phases, organic modifiers, and ion-pairing reagents. Guillarme highlighted that the platform successfully accelerated method development for several case studies.

Astrid Buica from AstraZeneca, BioPharma R&D, Sweden, presented on Towards a Smart Toolbox for PROTACs Separations: Learnings from Pharmaceutical Development Experience. Buica described a practical approach to the separation and purification of proteolysis-targeting chimeras (PROTACs), a rapidly developing class of therapeutics whose large and structurally diverse nature can create unusual chromatographic challenges.

Drawing on experience with more than 1700 PROTAC compounds, Buica's team identified recurring problems including poor dissolution, chemical instability, and unpredictable chromatographic behavior. Their investigations combined liquid and supercritical fluid chromatography (SFC) with several separation modes, including RPLC, normal-phase liquid chromatography (NPLC), HILIC, polar-organic mode (POM), and chiral chromatography.

Systematic studies provided practical insights into method selection. Screening more than 50 solvents revealed that many PROTACs have limited solubility in commonly used chromatographic solvents, whereas selected polar aprotic mixtures could improve dissolution. In a study of chiral PROTACs, extensive screening showed that NPLC generally provided more successful separations than SFC, although with longer analysis times. Work on achiral PROTACs also identified relationships between molecular characteristics and SFC retention that could assist column selection and method development.

These findings were incorporated into a decision-tree “smart toolbox” for selecting separation strategies according to molecular structure and stability. The approach highlights the value of combining systematic experimentation with practical experience to develop efficient methods while maintaining PROTAC integrity, according to Buica.

Jonathan Maurer from the University of Geneva, Switzerland, gave a presentation titled Putting a Cap on Complexity: mRNA Capping Analysis by IP-RPLC–UV. This research aimed to address the characterization of the 5′ cap, an important attribute of messenger ribonucleic acid (mRNA) products that can influence their biological performance. Rather than relying on mass spectrometry (MS), Maurer and colleagues decided to explore whether chromatographic selectivity combined with ultraviolet (UV) detection could provide sufficient discrimination between closely related capping forms.

The resulting workflow they devised used selective enzymatic processing to generate fragments containing the mRNA 5′ end, which can then be resolved by IP-RPLC. Careful optimization of the chromatographic system enabled discrimination of several cap-related species, including uncapped, Cap 0, and Cap 1 forms, as well as additional variants.

A systematic optimization strategy was used to establish conditions that balanced retention, resolution, and robustness. The final assay could be completed in approximately 20 min and showed good precision across repeated measurements. Importantly, measurements of Cap 1 and uncapped material agreed closely with those obtained using an ultrahigh-performance liquid chromatography–mass spectrometry (UHPLC–MS) reference method.

The work illustrates how fundamental chromatographic selectivity can replace some of the complexity associated with MS-based workflows, offering a potentially more accessible approach for routine monitoring of mRNA capping, according to Maurer.

Giacomo Russo from Edinburgh Napier University’s Centre for Biomedicine and Global Health, School of Applied Sciences, United Kingdom, concluded the session with Comprehensive LC×LC with Skin-Mimicking Stationary Phases for Dermal Permeability Assessment of Pharmaceutical and Toxicologically Relevant Compounds. Russo described a comprehensive two-dimensional liquid chromatography (LC×LC) method to investigate dermal permeability, using chromatographic stationary phases chosen to mimic different layers of the skin to provide a simplified model of this biological barrier.

The first dimension uses a skin-mimicking stationary phase representing the lipid-rich outer layer, while an immobilized artificial membrane phase in the second dimension models deeper membrane interactions. The method was tested against 43 pharmaceutical and cosmetic compounds with known transdermal permeability values, comparing chromatographic retention profiles with established permeability data to see whether regions of the two-dimensional separation space carry information about skin penetration. The work was supported by additional permeability measurements using Permeapad and by miniaturized chromatography run under mass-spectrometry-compatible conditions. The study shows how multidimensional biomimetic chromatography can reproduce features of a biological barrier and offer a practical way to study the permeability of pharmaceutical and other chemically relevant compounds.

References

1. ISC 2026 Program: https://www.czech-in.org/cmPortalv15/Searchable/isc26/config/normal#!sessiondetails/0000375340_0(accessed 2026-09-09).
2. Holčapek, M.; Nováková, L. ISC 2026 Preview. LCGC International 2026, 3 (5), 34.