Development and Activity Testing of Spray Dried Phosphorylated Hexaacyl Disaccharide for Nasal Administration

This scientific poster seminar will explore the development and activity testing of spray dried phosphorylated hexaacyl disaccharide for nasal administration. 

Key Message

Spray dried PHAD formulation has been developed for administration as a micellar nasal spray to treat viral respiratory infections and allergies. Investigations found that PHAD concentration within spray drying feed solutions influenced the reconstitution properties of the resultant powder formulations, with reconstitution time, solution turbidity and micelle uniformity affected.

Introduction

Phosphorylated Hexaacyl Disaccharide (PHAD) is a synthetic structural analogue of Monophosphoryl Lipid A (MPLA), a phospholipid with immunostimulatory activity ^[1]. 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+ T-cells ^[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 ^[4].

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.

Aim

To spray dry PHAD in its micellar form to produce a powder formulation that would reconstitute in water back to its original micellar form and produce an immune response.