Spray drying inhalable vaccines

Pharmaceutical lactose specialist MEGGLE has released a scientific paper on the potential of inhaled solid spray-dried formulations for vaccine delivery.

The paper ‘Optimizing the Aerodynamic Performance of Spray Dried mRNA Lipoplexes in Mannitol or Lactose Matrix’ is the result of a collaboration between MEGGLE and University of Kiel. The study is co-authored by MEGGLE scientists Ricarda Leister and Dr. Constanze Müller, along with Dr. Regina Scherließ and Dr. Jana Schembera from the University’s Department of Pharmaceutics and Biopharmaceutics.

Seeking stability

The study was prompted by concerns about the risks of chemical degradation and physical instability that affect some liquid vaccines, as well as the high potential for therapeutic interventions that target the respiratory tract, lungs and the mucosal immune system as the most common points of entry for respiratory pathogens.

It explores a possible role for solid formulations that can exhibit greater stability with less challenging storage conditions, combined with the suitability of spray drying as a Continuous Manufacturing (CM) method with high production capacity.

An inhalable vaccine platform

The team selected spray drying as a production technique on which to base formulation of an Inhalable Dry Powder Platform for mRNA Therapeutics. They incorporated firefly luciferase mRNA lipoplexes into spray dried matrixes formed from Mannitol or lactose-based matrices, with L-leucine added to some formulations.

The researchers found that co-spray drying with L-leucine in both matrices achieved significant reduction of powder residue in the inhaler capsules and considerably higher fine particle fractions (FPFs) by increasing surface hydrophobicity and thereby reducing electrostatic interactions.

The study was partly funded by the Aerosol Society and was presented as a poster to the 14th World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology in Vienna during March 2024.