Saparuddin Latu, Jangga, Abdul Wahid Suleman, Hardyanti Eka Putri, Sriyana Herman, Rifa’Atul Mahmudah, Rusli, Nurhikmah
Background: Grapefruit (Citrus maxima Merr.) peel is known to contain bioactive compounds such as alkaloids, tannins, and flavonoids, which exhibit potential antibacterial properties, particularly against acne-causing bacteria. Objective: This study aimed to formulate an anti-acne gel incorporating grapefruit peel extract, evaluate its antibacterial activity against Staphylococcus aureus (SA) and Propionibacterium acnes (PA), and determine the optimal extract concentration for inhibiting bacterial growth. Methods: A laboratory-based experimental study was conducted using the well diffusion (pitting) method to assess antibacterial activity. Gel formulations containing grapefruit peel extract at concentrations of 5%, 10%, and 15% were tested against SA and PA. Results: The formulated gels demonstrated acceptable physical stability. The inhibition zones against SA were as follows: 5% (F1) = 10.2 mm, 10% (F2) = 11.2 mm, and 15% (F3) = 11.1 mm. Against PA, the inhibition zones were: F1 = 11.7 mm, F2 = 13.3 mm, and F3 = 11.7 mm. The 10% formulation (F2) exhibited the highest antibacterial activity against both bacterial strains, falling within the "strong" inhibition category. Conclusion: Grapefruit peel extract can be successfully formulated into an anti-acne gel and demonstrates effective antibacterial activity against Staphylococcus aureus and Propionibacterium acnes. Among the tested concentrations, 10% was identified as the most effective for bacterial inhibition. © 2025 the Author(s).
Faculty of Pharmacy, University of Megarezky, Makassar, Indonesia; Magister of Pharmacy, Postgraduate Program, University of Megarezky, Makassar, Indonesia; Magister of Reproductive Health, Postgraduate Program, University of Megarezky, Makassar, Indonesia; Department of Physiotherapy, Faculty of Health and Sport Sciences, State University of Makassar, Indonesia; Department of physical education health and recreation, State University Muhammdiyah, Luwuk Banggai, Indonesia
