Benzoyl Peroxide

Benzoyl peroxide is a topical agent used in acne treatment. It has two main mechanisms of action: comedolytic (keratolytic) and antibacterial. The keratolytic effect helps break down comedones by promoting the shedding of follicular epithelial cells, reducing hyperkeratinization. The antibacterial action targets Propionibacterium acnes through strong oxidizing effects, generating free radicals that destroy bacterial proteins and lipids. This dual mechanism reduces existing lesions and helps prevent new ones. Benzoyl peroxide is often combined with topical antibiotics such as clindamycin or erythromycin to enhance efficacy, especially when monotherapy is less successful. When used alongside oral antibiotics, it reduces the risk of antibiotic-resistant bacterial strains.

Fig. 1 Pathogenesis of acne vulgaris and mechanism of action of drugs. (Seth V, Mishra A. 2015)

Dispersin B, an enzyme that degrades the exopolysaccharide poly-N-acetylglucosamine (PNAG), acts synergistically with benzoyl peroxide (BP) against dual-species biofilms of Cutibacterium acnes and Staphylococcus epidermidis. Treatment with dispersin B or BP alone reduces C. acnes colony-forming units by only 1–2 logs. However, sequential treatment with dispersin B followed by BP achieves a >6-log reduction, effectively eradicating C. acnes. Even low concentrations (5 µg/mL dispersin B combined with 0.5% BP) are highly effective. PNAG protects C. acnes from BP. Dispersin B enhances BP efficacy, which may lower the required BP dose and reduce skin irritation in acne treatment.

Fig. 2 Synergistic activity of dispersin B and benzoyl peroxide. (Kaplan J B.; et al. 2025)