Antibacterial efficacy of benzoyl peroxide in phospholipid liposomes - A vehicle-controlled, comparative study in patients with papulopustular acne

Background: Literature reports indicate that phospholipid liposomes facilitate the accumulation of active agents in the infundibulum. Objective: The study hypothesis of an improved antibacterial efficacy of benzoyl peroxide (BPO) in phospholipid liposomes was tested in comparison with a commercial and a pharmacopoeial BPO preparation. Methods: The infundibular bacterial samples were obtained with the Permabond technique from 20 acne patients who had been treated with the test substances (vehicle-controlled) for 2 weeks twice per day in a single-blinded, comparative study on the upper back. Results: A significant antibacterial effect in the infundibula (Propionibacteria and Micrococcaceae, both: p < 0.001) for a BPO phospholipid liposome formulation could be demonstrated. in comparison to the other significantly efficacious BPO formulations which were also tested (commercial product and pharmacopoeial formulation), the BPO phospholipid liposome formulation showed a significantly greater antibacterial efficacy for Propionibacteria and Micrococcaceae (both: p < 0.01). Conclusion: A BPO formulation in phospholipid liposomes may represent an improvement of the conventional external BPO treatment of acne.