Stability indicating ion-pair reversed-phase liquid chromatography method for modified mRNA.

Modified messenger RNA (mRNA) represents a rapidly emerging class of therapeutic drug product. Development of robust stability indicating methods for control of product quality are therefore critical to support successful pharmaceutical development. This paper presents an ion-pair reversed-phase liquid chromatography (IP-RPLC) method to characterise modified mRNA exposed to a wide set of stress-inducing conditions, relevant for pharmaceutical development of an mRNA drug product. The optimised method could be used for separation and analysis of large RNA, sized up to 1000 nucleotides. Column temperature, mobile phase flow rate and ion-pair selection were each studied and optimised. Baseline separations of the model RNA ladder sample were achieved using all examined ion-pairing agents. We established that the optimised method, using 100 mM Triethylamine, enabled the highest resolution separation for the largest fragments in the RNA ladder (750/1000 nucleotides), in addition to the highest overall resolution for the selected modified mRNA compound (eGFP mRNA, 996 nucleotides). The stability indicating power of the method was demonstrated by analysing the modified eGFP mRNA, upon direct exposure to heat, hydrolytic conditions and treatment with ribonucleases. Our results showed that the formed degradation products, which appeared as shorter RNA fragments in front of the main peak, could be well monitored, using the optimised method, and the relative stability of the mRNA under the various stressed conditions could be assessed.

The Storage and In-Use Stability of mRNA Vaccines and Therapeutics: Not A Cold Case.

The remarkable impact of mRNA vaccines on mitigating disease and improving public health has been amply demonstrated during the COVID-19 pandemic. Many new mRNA-based vaccine and therapeutic candidates are in development, yet the current reality of their stability limitations requires their frozen storage. Numerous challenges remain to improve formulated mRNA stability and enable refrigerator storage, and this review provides an update on developments to tackle this multi-faceted stability challenge. We describe the chemistry underlying mRNA degradation during storage and highlight how lipid nanoparticle (LNP) formulations are a double-edged sword: while LNPs protect mRNA against enzymatic degradation, interactions with and between LNP excipients introduce additional risks for mRNA degradation. We also discuss strategies to improve mRNA stability both as a drug substance (DS) and a drug product (DP) including the (1) design of the mRNA molecule (nucleotide selection, primary and secondary structures), (2) physical state of the mRNA-LNP complexes, (3) formulation composition and purity of the components, and (4) DS and DP manufacturing processes. Finally, we summarize analytical control strategies to monitor and assure the stability of mRNA-based candidates, and advocate for an integrated analytical and formulation development approach to further improve their storage, transport, and in-use stability profiles.

Designing flexible low-viscous sieving media for capillary electrophoresis analysis of ribonucleic acids.

Modified messenger RNA (mRNA) has recently become a new prospective class of drug product. Consequently, stability indicating separation methods are needed to progress pharmaceutical development of mRNA. A promising separation technique for the analysis of mRNA is capillary gel electrophoresis (CGE). We designed a flexible, low-viscous sieving medium for CGE, based on high mass linear polyvinylpyrrolidone (PVP) and glycerol. A Central Composite Face-centered design resulted in a strong model that allowed us to predict suitable sieving media compositions by using multi-objective optimization. The way of working proposed in this paper gives analysts the freedom to design a suitable sieving medium for their response(s) of interest, for purity and stability analysis of polynucleotides with a size around 100-1000 bases. Depending on the criteria for the analysis there will be a trade-off between different suitable conditions. By using this method, we created a sieving medium that was able to improve resolution, peak height and analysis time of an RNA ladder compared to the current commercially available separation gels.