Antibacterial and anti-tyrosinase activity of eucalyptus leaf [Melaleuca leucadendra (L.) L.] acne spot emulgel: Formulation and evaluation

Context: The eucalyptus plant [Melaleuca leucadendra (L.) L.] is one of the plants that has long been used in various traditional and modern medicines. This plant contains numerous active compounds and is beneficial for treating various conditions, including inflammation, pain, diabetes, and cancer. Aims: To formulate an acne spot emulgel containing M. leucadendra leaf extract and to evaluate its antibacterial and anti-tyrosinase activities. Methods: The extract was obtained by maceration using dichloromethane. Emulgels were prepared using Carbomer 940 as the gelling agent, with three extract concentrations tested (F1, F2, and F3). The formulations were assessed through organoleptic properties, pH, viscosity, spreadability, cycling stability, and irritation tests. Antibacterial activity was determined against Staphylococcus epidermidis and Propionibacterium acnes using the disc diffusion and dilution method. Anti-tyrosinase activity was evaluated based on its IC50 value. Results: The F3 formulation demonstrated the highest antibacterial activity, with inhibition zones of 19.5 mm (MIC 250 mg/mL and MBC 250 mg/mL) and 14.27 mm (MIC 125 mg/mL and MBC 125 mg/mL) against S. epidermidis and P. acnes, respectively. The IC50 value of 271 μg/mL indicated weak inhibition of tyrosinase. Conclusions: These findings suggest that M. leucadendra-based emulgel is a promising candidate for acne treatment. However, further studies, including in vivo assessments, are recommended.