Formulation and Evaluation of Citronella Oil (Cymbopogon nardus (L.) Rendle) Cream for Acne Treatment

Acne is a prevalent skin disorder that aff ects 80–85% of teenagers globally. Citronella oil is one of the natural compounds that has been known to potentially treat acne, but its application is limited due to its greasiness and uncomfortable sensation on skin. This study aimed to optimize the concentration of cetyl alcohol as a viscosity enhancer that can produce a physically stable cream preparation and to evaluate the antibacterial activity of the optimized formula against Propionibacterium acnes. Following the emulsifi cation process, the physical characteristics of the fi ve cream formulas, including organoleptic, homogeneity, emulsion type, pH, adhesion, specifi c gravity, viscosity, and stability were evaluated. Formula 3 (F3), cream formulation with 6% cetyl alcohol having physical characteristics of a white homogeneous cream with a pronounced lemongrass scent, emulsion type o/w, pH of 6.30 ± 0.02, adhesion of 16.85 ± 0.58 s, a specifi c gravity of 1.031 ± 0.009 g/mL, and viscosity of 4418 ± 182 m Pas was chosen as the optimized formula. F3 was then subjected to antibacterial testing against P. acne and showed a 9.35 mm inhibition zone. Cream-based citronella oil, therefore, becomes a promising preparation for acne treatment