Introduction: Betel leaf ethanol extract (Piper betle L.) has antibacterial activity against P. acnes because it contains tannins, flavonoids, alkaloids, and terpenoids. The purpose of this study was to formulate the ethanol extract of betel leaf into a sheet mask preparation that fulfills the requirements of physical quality and physical stability and performing an antibacterial activity test against P. acnes.

Method: Sheet masks were prepared into 4 different formulas (contain 0%, 1%, 1.5%, and 2% of extract) and then examined for the physical quality (organoleptic, homogeneity, pH, and viscosity) and freeze-thaw stability. Organoleptic and homogeneity test data were analyzed descriptively. The pH and viscosity test data were statistically analyzed using the one-way ANOVA method. The selected formula was tested for antibacterial activity against P. acnes using the diffusion method.

Results: All formulas of sheet masks containing betel leaf ethanol extract have fulfilled the requirements. There was no change in shape, color, and odor during 28 days of storage, homogeneous, had a pH of 4.9-5.6, a viscosity of 250-410 cps, and was stable in the freeze-thaw testing.

Conclusions: Formula 2 contains 1.5% of betel leaf ethanol extract is selected as the best formula of sheet mask. Formula 2 has an inhibitory zone diameter against P. acnes in the strong category of 24.67 mm.

Keywords: Betel leaf, antibacterial activity, P. acnes, sheet mask