Lipid nanoparticles (LNPs) provide the most advanced platform for in vivo drug delivery of nucleic acids. However, they are not yet well-characterized biopharmaceuticals. Among others, challenges are of biological, manufacturing, and characterization type. Manufacturing challenges include correctly forming the drug product, maintaining its integrity, achieving sufficient recovery, and obtaining a well-purified and characterized product.
Tangential flow filtration (TFF) has been implemented to scale up downstream processing for the Comirnaty and the Spikevax vaccines. TFF may result in low recovery of the encapsulated RNA, ranging around 50%. Thus, an alternative to the TFF process, a new separation process has been developed using CIM Convective Interaction Media® OH monolithic columns. CIM® monolithic columns are uniquely suitable for LNP purification due to the low shear stress imparted of the purely laminar flow and a wide selection of chemically modified surfaces. LNPs are loaded onto the columns under kosmotropic conditions, directly following the encapsulation process and neutralization. This process, which is much faster than comparable TFF processes, achieves the desired concentration, ethanol removal, and buffer exchange functions. At the same time, free, non-encapsulated RNA is removed by tuning the buffers and achieving chromatographic separation. Subpopulations of the sample are also collected, with the most active portion of the drug product retained.
Additionally, analytical methods developed using PATfix® LNP Switcher Platform enable the characterization of such formed drug products. They allow the determination of mRNA quantity and purity inside LNPs, mRNA-lipid adduct quantity, and lipid purity.
