Effect of Surfactant Concentration on Physicochemical and Antibacterial Properties of Eugenol Nanoemulsions

Abstract

Introduction:: Nanoencapsulation has gained popularity in recent decades due to its numerous benefits, such as improved stability, oxidation resistance, retention of volatile ingredients, controlled release, delivery of multiple active ingredients in a row, improvement in organoleptic properties, reduction of toxic side effects, and water solubility. Methods:: The present study was aimed to prepare eugenol nanoemulsions (EuNEs) using non-ionic surfactant (Tween 80) by ultrasound-assisted techniques and to evaluate the effects of surfactant concentration on their droplets size, polydispersity index (PDI), zeta potential, storage stability, antioxidant, and antibacterial activities. Antimicrobial activity of the prepared nanoemulsions was tested against Gram-positive; Staphylococcus aureus, Bacillus subtilis and Gram-negative; Escherichia coli, and Alcaligenes faecalis bacteria using well diffusion method. Results:: The results showed that the droplet size decreased after a threshold Tween 80 concentration (10%), while PDI value increased with the increase in surfactant concentration (Tween 80). method: The droplets size, poly dispersity index (PDI), zeta potential, storage stability, antioxidant, and antibacterial activities of the prepared nanoemusions were characterized. Conclusion:: The prepared EuNEs exhibited good antibacterial activity against all the four bacterial strains: E. coli, A. faecalis, S. aureus, and B. subtilis. conclusion: No phase separation, creaming, layering or deposition of large oil droplet were observed in the prepared nanoemulsions (EuNE-5, EuNE-7.5, and EuNE-10) except in case of 15%, v/v Tween 80 (EuNE-15) during 30 days of storage