Microencapsulated benzoyl peroxide cream alters skin microbiota, improves rosacea

Treatment with a microencapsulated benzoyl peroxide (E-BPO) 5% cream contributes to changes in the microbiome of the skin and results in improvements in moderate to severe rosacea, according to a study presented at the recent WCD 2023.

Specifically, “E-BPO reduced the relative abundance of Staphylococcus while increasing Cutibacterium, [and] demonstrated significantly sustained improvement in the severity of erythema,” said the researchers, led by Yvonne Nong from the Integrative Skin and Science Research, Sacramento, US.

Nong and her team carried out an 8-week, double-blind, 1:1 randomized, vehicle-controlled clinical study. Subsequently, they did a crossover study for an additional 4 weeks and then another 4 weeks of observation to determine whether E-BPO altered the skin microbiota in patients with rosacea.

Thirty-four patients with moderate to severe rosacea were included in the study and divided into two crossover treatment groups. The researchers obtained skin microbiome samples at baseline, postapplication, and weeks 1, 2, 4, 8, and 12. They then analysed the samples using shotgun metagenomic whole-genome sequencing.

At all visits, Yvonne and colleagues performed the rosacea Investigator Global Assessment (IGA) score, lesion counts, erythema severity, rosacea inflammation evaluation, and skin biophysical measurements. They also measured redness, darkness, and luminosity at each visit using a skin colorimeter. These characteristics were evaluated and recorded based on the L*a*b objective criteria for lightness, red/green, and yellow/blue assessments.

From baseline to week 8, a decrease was observed in the relative abundance of Staphylococcus (p=0.1061) and an increase in Butibacterium (p=0.0341) in the E-BPO group, whereas no changes were seen in the vehicle group. Notably, neither of the treatment groups showed any changes in the microbial diversity (Shannon diversity index). [Nong Y, et al, World Congress of Dermatology 2023]

Improvements in the IGA score, as determined by the percentage of patients achieving a score equating to “clear” or “almost clear,” was higher in the E-BPO group (range, 0 percent to 78.57 percent) than in the vehicle cream group (range, 0 percent to 37.5 percent) at each postbaseline visit. Additionally, colorimeter measurements demonstrated improvements in erythema.

Sol-gel process

A recent review summarizing drug delivery systems that have been developed with the aim of improving outcomes for patients being treated for either acne or rosacea reported that microencapsulation of BPO and tretinoin with the sol-gel process produced medications with significant efficacy and good tolerability in patients with either of the two conditions. [J Clin Aesthet Dermatol 2022;15:36-40]

In another study reviewed, results showed that a polymeric formulation of tretinoin had a favourable safety and tolerability profile with fewer incidences of erythema, dryness, and skin burning compared with other formulations of the drug. [J Dermatol Treat 2020;31:160-167]

“Greater rates of clinical success are expected as these advanced drug delivery systems continue to improve, which, along with enhancements in vehicle technology, serve to amplify the product’s efficacy without sacrificing tolerability,” according to the authors.