Guava leaf (Psidium guajava L.) contains flavonoids and tannins which have bacterial activity against Staphylococcus aureus. The use of extract as an antibacterial is not practical to use so it is made in gel form. The purpose of this study was to determine the effect of variations in the concentration of guava leaf ethanol extract on the physical properties of the gel and determine the inhibitory zones produced from the ethanol extract of guava leaves. The extract was obtained from maceration with 70% ethanol, and then it was made in gel form. The gel formula was made on the basis of CMC-Na and the ethanol extract content of guava leaves used 1, 5, and 7%. Gel evaluation includes organoleptic, homogeneity, adhesion, viscosity, pH, dispersal, and cycling tests which are then carried out with antibacterial tests using the bacteria of Staphylococcus aureus. The concentration of guava leaves ethanol extract has a significant effect on gel stability and antibacterial activity. The higher concentration of ethanol extract of guava leaves shows the higher zone of bacterial inhibition, adhesion, viscosity, and decreased pH and gel dispersion.

Keywords : Gel, Guava Leaves, Antibacterial, Staphylococcus aureus