<![CDATA[Betel nuts contain secondary metabolites that have antibacterial activity. Cosmetic products that are often used as antibacterial agents are liquid soaps. The antibacterial potential of liquid soap against the bacterium Propionibacterium acnes (P. acnes) needs to be developed.P. acnes is a bacterium that plays a role in the formation of acne. The research aims to analyze the antibacterial activity and physical properties of palm seed extract liquid soap against P. acnes. The type of research used is experimental with a post-test control group design. The antibacterial activity test method used was the disk diffusion method. The liquid soap formulations, formulas 1, 2, and 3, contain extract concentrations of 1%, 3%, and 5%, respectively, and physical characteristics were observed on organoleptic parameters, pH, foam height, and viscosity over 28 days. The inhibition zone diameter data was analyzed using the One Way Anova and LSD statistical tests. Liquid soap formulas 1, 2, and 3 have organoleptic characteristics that are semi-viscous, brown in color, have a distinctive betel nut scent, and are homogeneous. Storage for 28 days showed no changes in organoleptic properties, pH value, foam height, and viscosity. Liquid soap formulas 1, 2, and 3 have antibacterial activity with average inhibition zone diameters of 14.1±0.59 mm (strong), 16.9±0.26 mm (strong), and 20.0±0.44 mm (very strong), respectively. The increase in the concentration of areca nut seed extract significantly affects the inhibition zone. ABSTRAK Biji pinang mengandung metabolit sekunder yang memiliki aktivitas antibakteri. Produk kosmetik yang sering digunakan sebagai antibakteri adalah sabun cair. Potensi antibakteri sabun cair terhadap bakteri Propionibacterium acnes (P. acnes) perlu dikembangkan. P. acnes merupakan bakteri yang berperan terhadap terbentuknya jerawat. Tujuan penelitian untuk menganalisis aktivitas antibakteri dan sifat fisik sabun cair ekstrak biji pinang terhadap P. acnes. Jenis penelitian yang digunakan adalah eksperimental dengan desain post test control group design. Metode uji aktivitas antibakteri menggunakan metode difusi cakram. Formulasi sabun cair formula 1, 2 dan 3 mengandung konsentrasi ekstrak berturut – turut sebesar 1%, 3% dan 5% dilakukan pengamatan karakteristik fisik pada parameter organoleptis, pH, tinggi busa, dan viskositas selama 28 hari. Analisis data diameter zona hambat dilakukan menggunakan uji statistic One Way Anova dan LSD . Sabun cair formula 1, 2, dan 3 memiliki karakteristik organoleptis berbentuk semi kental, berwarna coklat, berbau khas pinang dan homogen. Penyimpanan selama 28 hari tidak menunjukkan perubahan organoleptis, nilai pH, tinggi busa dan viskositas. Sabun cair formula 1, 2, dan 3 memiliki aktivitas antibakteri dengan diameter zona hambat rata – rata berturut – turut sebesar 14,1±0,59 mm (kuat), 16,9±0,26 mm (kuat), dan 20,0±0,44 mm (sangat kuat). Peningkatan konsentrasi ekstrak biji pinang mempengaruhi zona hambat secara signifikan.]]>
