The administration of therapeutics by nasal delivery is a growing area of pharmaceutical development, due to the ease of administration and large, vascularised surface area available in the nostril. However, there is a risk of pulmonary administration if powders are within the respirable range. Inhalable particles are defined by several industries as those with a particle diameter of 10 µm or less  , however the method of defining powder particle diameter is not clear. There is currently limited pharmacopeial guidance on the testing of nasal powders delivered from single dose nasal device.
Whilst laser diffraction is commonly used by the pharmaceutical industry to define particle diameter and included as part of target product profiles for nasal products, a more biorelevant test method is required that evaluates the combination of formulation and device.
The main objective of the MACIVIVA European consortium was to develop new Good Manufacturing Practice pilot lines for manufacturing thermostable vaccines with stabilized antigens on influenza virosomes as enveloped virus-like particles. The HIV-1 gp41-derived antigens anchored in the virosome membrane, along with the adjuvant 3M-052 (TLR7/8 agonist) on the same particle, served as a candidate vaccine for the proof of concept for establishing manufacturing processes, which can be directly applied or adapted to other virosomal vaccines or lipid-based particles.
Poster Introduction : Phosphorylated Hexaacyl Disaccharide (PHAD) is a synthetic structural analogue of Monophosphoryl Lipid A (MPLA), a phospholipid with immunostimulatory activity. When in micellar form, it activates Toll-like receptor 4 (TLR4), leading to the production of protective cytokines and chemokines, and activation of CD4+ and CD8+ Tcells [1,2,3].
It is believed that PHAD must be in particle form, like a micelle, for best recognition and binding to TLR4, likely
as the micellar shape mimics a globular protein.
Micelles can be prepared by wetting PHAD with a solvent and adding water. However, liquid solutions have shown poor solubility and high irritation on administration due to the presence of the non-aqueous solvent.