Insulin, insulin-like growth factor-1 (IGF-1) and essential amino acids activate the mechanistic target of rapamycin complex 1 (mTORC1), the main nutrient-sensitive kinase. Metformin, through inhibition of mTORC1 may improve acne. A 12-week, randomized, open-labeled study evaluated the efficacy and safety of metformin as an adjunct for moderate to severe facial acne. In total, 84 patients received either oral tetracycline 250 mg bd and topical benzoyl peroxide 2.5% with or without metformin 850 mg daily. Evaluations constituted lesion counts, the Cardiff Acne Disability Index (CADI), metabolic parameters and treatment success rate (Investigators Global Assessment score of 0 or 1 or improvement of two grades). Treatment success rates were higher in the metformin group (66.7% vs. 43.2%; p = .04). The mean percentage reduction from baseline in total lesion counts at Week 12 was greater in the metformin group (71.4% vs. 65.3%; p = .278). The CADI scores showed a greater mean reduction in the metformin group (4.82 vs. 4.22; p = .451). Metformin was equally efficacious in improving acne in lean and overweight subjects. Gastrointestinal symptoms were noted in 31.7% of subjects on metformin. This study presents favorable data for metformin as an adjunct for acne treatment. Further randomized placebo-controlled studies are required.
Topical keratolytic agents such as benzoyl peroxide (BP) and salicylic acid (SA) are one of the common treatments for inflammatory skin diseases. However, the amount of drug delivery through the skin is limited due to the stratum corneum. The purposes of this study were to investigate the ability of fish oil to act as penetration enhancer for topical keratolytic agents and to determine the suitable gelator for formulating stable fish oil oleogels. 2 types of gelling agents, beeswax and sorbitan monostearate (Span 60), were used to formulate oleogels. To investigate the efficacy of fish oil oleogel permeation, commercial hydrogels of benzoyl peroxide (BP) and salicylic acid (SA) were used as control, and comparative analysis was performed using Franz diffusion cell. Stability of oleogels was determined by physical assessments at 20°C and 40°C storage. Benzoyl peroxide (BP) fish oil oleogels containing beeswax were considered as better formulations in terms of drug permeation and cumulative drug release. All the results were found to be statistically significant (p<0.05, ANOVA) and it was concluded that the beeswax-fish oil combination in oleogel can prove to be beneficial in terms of permeation across the skin and stability.
OBJECTIVE: Comparative trials of benzoyl peroxide (BPO) have yielded contradictory results on its effectiveness for acne vulgaris. The aim of the study was to synthesise the evidence for the effectiveness of BPO-containing topical products for facial acne vulgaris.
DESIGN: Systematic review.
METHODS: The Cochrane Central Register of Controlled trials, Cochrane Library, MEDLINE and other relevant databases were searched without publication date or language restriction.
RESULTS: We identified 22 trials involving 2212 participants; 12 trials compared BPO as single agent while the other 10 trials compared BPO in combination products. All trials reported lesion count as the outcome measure but only five trials provided numerical data. However, pooling of data from these trials was inappropriate due to variations between trials in terms of acne severity, comparator used and trial duration. Overall the study quality was fair but most studies had some bias particularly in method of random generation and allocation concealment. Although the results provide some evidence that BPO reduces acne-lesion count, the available evidence is not robust enough for firm conclusions.
CONCLUSIONS: There is no high quality evidence that topical BPO improves facial acne vulgaris, and further research is needed.