A clinical study on the tolerability of a liposomal povidone-iodine nasal spray: implications for further development

This phase I study assessed tolerability and local effect of a liposome dispersion with povidone-iodine (polyvinylpyrrolidone-iodine, PVP-I) as nasal spray.

Three groups received liposomal dispersion with PVP-I (2.2, 4.4 and 0% as control) in single and repeated use (3 days, three times a day). A set of functional and cytological tests as well as safety assessments were performed.

No safety-relevant finding or serious adverse events were reported, no evidence for cyto- nor genotoxicity obtained. No clinically relevant changes in mucosa appearance, nor in olfactory sense, nor in ciliary activity (sensitive indicator of local tolerance) occurred and no complaints about nasal airflow obstruction were observed. All liposomal formulations had a positive effect on the nasal mucosa, challenged by allergy in some volunteers. CONCLUSIONS AND MESSAGE: Application of liposomal PVP-I spray to the nasal mucosa does not result in any demonstrable limitation of the nasal function nor in detectable damage to the multilayer ciliated epithelium of the nose. Improvement of various parameters of nasal function under liposomal PVP-I suggest improved mucociliary clearance. Explanation could be humidification, improved surfactant (phospholipid) level and/or sufficient mucolytic activity of iodide due to local application of the constituents.