eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2026-05-19 19 2 71897 article Mazlin Mohideen 1 Dhia Ali Fudail Che Rosli 1 Wan Ahmad Irfan Hakimi Wan Abd Malik 1 Nur Azzalia Kamaruzan 2 Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, Ipoh Perak, Malaysia National Poison Centre, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia Oral infections remain a significant public health concern, and prolonged use of chlorhexidine mouthwashes may cause adverse effects such as tooth staining and mucosal irritation. Consequently, increasing attention has been directed toward the development of plant-based oral healthcare products with antimicrobial properties and improved safety profiles. This study evaluated the antimicrobial activity of an ethanolic extract of Piper betle L. leaves and its application in a herbal mouthwash formulation. The extract was prepared by maceration and subjected to qualitative phytochemical screening. Antimicrobial activity was assessed using the disc diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The extract exhibited measurable antimicrobial activity, with inhibition zones ranging from 24.00 ± 2.00 mm to 26.00 ± 1.00 mm against S. aureus, 16.33 ± 1.53 mm to 18.00 ± 1.00 mm against P. aeruginosa, and 26.00 ± 1.73 mm to 27.33 ± 1.53 mm against C. albicans. Two mouthwash formulations containing 150 mg and 250 mg extract per 100 mL were prepared and evaluated for physicochemical characteristics and short-term stability. Both formulations demonstrated acceptable characteristics, with pH values ranging from 5.90 to 6.58, good clarity, moderate foaming capacity, and stability over a seven-day storage period. These findings suggest that Piper betle extract has potential as a natural antimicrobial ingredient for oral healthcare formulations, although further studies including quantitative antimicrobial analysis, long-term stability testing, and clinical evaluation are required. https://biomedpharmajournal.org/vol19no2/formulation-and-preliminary-antimicrobial-evaluation-of-an-ethanolic-piper-betle-l-leaf-extract-herbal-mouthwash/ Antifungal Activity Antimicrobial Activity Herbal Mouthwash Oral Pathogens Piper betle Phytochemical Screening