Soap is a cosmetic product that acts as a cleansing agent to prevent the occurrence of skin infections and other bodily diseases caused by bacterial and fungal infections. One of the bacteria that causes skin infection is Staphylococcus aureus. The eugenol content in cloves and cinnamaldehyde in cinnamon can inhibit the growth of bacteria. This research aimed to examine a liquid soap formulation based on a nanoemulsion combination of clove (Syzygium aromaticum) and cinnamon (Cinnamomum burmannii) essential oils that met the physicochemical characteristics and determine its activity in inhibiting the growth of S. aureus using the paper disk diffusion method. The results suggested that the use of the 2% clove essential oil and 3% cinnamon essential oil exhibited effective antibacterial activity These concentrations were then used to formulate a nanoemulsion with a composition ratio of Tween 80 and PEG 400 as the most optimal surfactant and cosurfactant of 40:10. The nanoemulsion was formulated into a liquid soap with the supplementation of clove and cinnamon essential oils to the liquid soap base for maintaining stability, improving the physical appearance of the soap, and promoting the antibacterial activity of clove and cinnamon essential oils in inhibiting the growth of S. aureus bacteria. The resulting liquid soap demonstrated good physicochemical properties and met the requirements.
