Investigation of the influence of hyaluronic acid molecular weight on characteristics and behaviour of nanoparticles for pulmonary drug delivery

A method to produce sodium hyaluronate (HA) nanoparticles by anti-solvent precipitation using ethanol as anti-solvent was developed. The significant effects of HA molecular weight, volume of anti-solvent and temperature on particle size and size distribution were highlighted. Amphotericin B, Fluconazole and Dexamethasone, three candidate drugs for pulmonary delivery, were then successfully loaded into nanoparticles employing HA with different molecular weights to exploit both the technological and the biological properties of the polymer. For loading, different methods and solvents were used according to the different solubilities of the drugs. Spray drying technique was then employed to convert the alcoholic nanosuspensions into nano-embedded microparticles suitable for inhalation, then characterized to assess their aerodynamic performances and solid-state properties.