Intranasal Vaccine Formulation: Advancing Towards Nasal Dry Powder Formulation

Unlike conventional mRNA vaccines, intranasal vaccines display several advantages, including the ability to generate strong mucosal immunity. However, the formulation challenges associated with intranasal mRNA vaccines have so far hindered their extensive application and further research in the area of formulation development and optimisation are required before translation. This study aims to optimise the manufacturing conditions of inhalable dry powders by examining the impact of temperature and lipid composition on liposome particle size and the effect of spray-drying parameters on the particle size of spray-dried powders. The results indicate that liposomes generated at 20°C exhibited notably larger sizes than those produced at 55°C, irrespective of the lipid composition. Notably, dry powder formulations featuring larger particle sizes were achieved at a low gas flow rate of 25mm.