In vitro evaluation of nebulized eucalyptol nano-emulsion formulation as a potential COVID-19 treatment

• Published in: Saudi pharmaceutical journal Vol. 30; no. 12; pp. 1691 - 1699
• Main Authors: Tulbah, Alaa S., Bader, Ammar, Ong, Hui Xin, Traini, Daniela
• Format: Journal Article
• Language: English
• Published: Saudi Arabia Elsevier B.V 01.12.2022; Published by Elsevier B.V. on behalf of King Saud University; Elsevier
• Subjects: 1,8-cineole; COVID-19; Cytotoxicity; Eucalyptol; Nano-emulsion; Original; Tween 80; COVID-19; Eucalyptol; Nano-emulsion; Cytotoxicity; 1,8-cineole; Tween 80
• ISSN: 1319-0164; 2213-7475
• DOI: 10.1016/j.jsps.2022.09.014

[Display omitted] Coronavirus is a type of acute atypical respiratory disease representing the leading cause of death worldwide. Eucalyptol (EUC) known also as 1,8-cineole is a potential inhibitor candidate for COVID-19 (main protease-Mpro) with effective antiviral properties but undergoes physico-chemical instability and poor water solubility. Nano-emulsion (NE) is a promising drug delivery system to improve the stability and efficacy of drugs. This work focuses on studying the anti- COVID-19 activity of EUC by developing nebulized eucalyptol nano-emulsion (EUC-NE) as a potentially effective treatment for COVID-19. The EUC -NE formulation was prepared using Tween 80 as a surfactant. In vitro evaluation of the EUC-NE formulation displayed an entrapment efficiency of 77.49 %, a droplet size of 122.37 nm, and an EUC % release of 84.7 %. The aerodynamic characterization and cytotoxicity of EUC-NE formulation were assessed, and results showed high lung deposition and low inhibitory concentration. The antiviral mechanism of the EUC-NE formulation was performed, and it was found that it exerts its action by virucidal, viral replication, and viral adsorption. Our results confirmed the antiviral activity of the EUC-NE formulation against COVID-19 and the efficacy of nano-emulsion as a delivery system, which can improve the cytotoxicity and inhibitory activity of EUC.