Host: The Japanese Society of Toxicology
Spray-freeze-drying (SFD) technique is suitable to prepare porous powders for inhalation. Hydrophobic amino acids were effective to obtain SFD powders with both a favorable inhalation performance and antihygroscopic property. We prepared naked pDNA powders by SFD technique with various excipients and a pDNA encoding firefly luciferase. The powder including low molecular weight hyaluronic acid (LHA) as an excipient showed high gene expression and low cytotoxicity. In-vitro inhalation characteristics were significantly improved by the addition of dispersing agent such as L-phenylalanine.
