Formulation of anti-acne concealer containing cinnamon oil with antimicrobial activity against Propionibacterium acnes

This study aimed to develop an anti-acne concealer containing essential oil with anti-Propionibacterium acnes activity. Antimicrobial activity of cinnamon oil, galangal oil, and eucalyptus oil against P. acnes DMST 14916 was assayed using agar disc diffusion and the broth dilution method. Cinnamon oil showed the maximum inhibitory activity against P. acnes with a clear zone diameter of 36.75 +/- 1.06 mm, compared to 14.67 +/- 0.58 and 41.83 +/- 1.04 mm for tea tree oil and clindamycin, respectively. The minimum inhibitory concentration value of cinnamon oil was 5 mg/mL. Among five formulations of concealer incorporating 0.5% w/w cinnamon oil, F4 provided good texture, coverage, and spreadability with anti-P. acnes activity and stable under determined storage conditions. Cinnamon oil could be a promising cosmetic ingredient for anti-acne products, and F4 concealer may be useful for both covering skin imperfections and the management of acne.