Safety in Rats of a Novel Nasal Spray Formulation for the Prevention of Airborne Viral Infections

Hexedra+((R)) is a nasal spray containing hydroxypropyl methylcellulose, beta-cyclodextrin, and usnic acid. It has been developed with the aim of reducing the risk of transmission of airborne viral infections, with particular reference to influenza and COVID-19. As part of the preclinical development of the product, we carried out a study on thirty male Wistar rats divided into three study groups and treated with Hexedra+, an alternative formulation containing a double concentration of usnic acid (0.015% instead of 0.0075%) or saline solution. Products were administered at the dose of 30 mu L into each nostril, three times a day for seven consecutive days by means of a micropipette. By the end of the treatment period, no significant changes were observed in body weight. Histological examination of nasal mucosa and soft organs did not show any significant difference in the three study groups. Serum transaminase level remained in the normal limit in all the animals treated. The serum level of usnic acid was measured in order to assess the absorption of the molecule through the nasal mucosa. By the end of the study period, the usnic acid serum level was negligible in all the animals treated. In conclusion, the safety profile of Hexedra+ appears favorable in the animal model studied.

Automated summary

Hexedra+ is a nasal spray formulated with hydroxypropyl methylcellulose, beta-cyclodextrin, and usnic acid. It aims to reduce the risk of airborne viral infections, specifically targeting influenza and COVID-19. A study conducted on male Wistar rats showed that the safety profile of Hexedra+ was favorable, with no significant changes in body weight or histological differences observed. Usnic acid absorption through the nasal mucosa was negligible in the animals treated.