Systems for lipid nanoparticle (LNP) production

Importance of Topic

Lipid nanoparticles (LNPs) have emerged as a critical delivery platform for nucleic-acid therapeutics such as mRNA, siRNA, and DNA. Their advantages include high encapsulation efficiency, biocompatibility, biodegradability, and scalable production workflows. Robust mixing technologies are essential to control particle size, polydispersity, and reproducibility during LNP formation.

Goals and Overview

This application note reviews the design and performance of KNAUER’s Impingement Jets Mixing (IJM) systems—specifically the benchtop NanoScaler and production-scale NanoProducer units—to streamline LNP formulation from research through preclinical and commercial stages. It also illustrates process optimization studies performed in collaboration with Curapath for mRNA encapsulation.

Methodology and Instrumentation

The core of the IJM approach is a high-velocity collision of two fluid streams in a jet mixer:

• Organic phase containing lipids in ethanol
• Aqueous phase containing API (e.g., mRNA) in buffer

Upon collision, rapid solvent dilution triggers nanoparticle self-assembly. Key instrumentation includes:

• High-pressure dosing pumps (80P series)
• Coriolis flow meters for real-time monitoring
• Custom IJM mixers with interchangeable geometries
• Quench and dilution manifolds, sterile filtration skids
• CDS-compliant control software (21 CFR part 11, GAMP 5)

Main Results and Discussion

Studies demonstrated that:

• IjM-produced LNPs match or exceed quality metrics achieved by microfluidic herringbone mixers, with Z-average diameters around 80–120 nm and low polydispersity index (PdI < 0.2).
• Particle size can be tuned inversely with total flow rate; higher flow yields smaller diameters.
• Encapsulation efficiency consistently exceeded 93% across multiple scales (1 mL to 50 mL batches).
• Scalable transfer from the NanoScaler to larger NanoProducer units preserves size distribution and reproducibility.

Benefits and Practical Applications

The IJM platform offers:

• Flexible bench-scale screening of mixer geometry, flow ratio, and dilution steps to minimize API consumption.
• Smooth scale-up from milliliter to liter volumes without redesigning mixing technology.
• Compact, CIP-compatible stainless-steel skids for GMP-ready manufacturing.
• Remote monitoring and automated data logging for process validation.

Future Trends and Potential

Upcoming developments may include:

• Integration of real-time analytical sensors (e.g., on-line DLS) for adaptive process control.
• Further miniaturization and modular expansion for parallel screening of multiple formulations.
• Advanced mixer designs tailored for novel lipid chemistries and targeted delivery vectors.
• Automation of end-to-end workflows, from formulation through sterile fill-finish.

Conclusion

KNAUER’s Impingement Jets Mixing technology, embodied by the NanoScaler and NanoProducer systems, provides a versatile and scalable solution for high-quality LNP production. Its ability to maintain consistent physicochemical properties across scales and its compatibility with regulatory-compliant instrumentation make it an industry-proven approach for accelerating nucleic-acid therapeutic development.

References

1. Polack, F. P., et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2. Baden, L. R., et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med.