Efficacy and safety of a new topical gel formulation containing retinol encapsulated in glycospheres and hydroxypinacolone retinoate, an antimicrobial peptide, salicylic acid, glycolic acid and niacinamide for the treatment of mild acne: preliminary results of a 2-month prospective study

BACKGROUND: Acne vulgaris is a common and chronic skin disease that impacts on physical and psychological perceptions. Combination therapy with topical retinoids and antimicrobial agent is considered the preferred approach for most of the subjects affected by mild-to-moderate acne. A correct therapeutic management should include a prolonged treatment to ensure therapeutic success and to prevent recurrences. The aim of this study was to evaluate the efficacy and tolerability of a new topical gel formulation that combines retinol encapsulated in glycospheres and hydroxypinacolone retinoate, associated with an anti-microbial peptide (BIOPEP-15) salicylic acid, glycolic acid, and niacinamide as monotherapy in mild acne vulgaris. METHODS: A 2-month prospective study was conducted at the Unit of Dermatology of the Federico II University. Twenty-five patients aged from 14 to 30 years with mild acne of the face (GAGS score ≤ 18) were consecutively enrolled. Each patient was asked to apply the gel formulation once daily in the evening for 8 weeks. The number of acne lesions with VISIA camera system, the global acne grading system (GAGS) score, trans epidermal water loss (TEWL), skin colorimetry (X-rite Spectrocolorimeter), reflectance confocal microscopy exam were evaluated at baseline, after 4 and 8 weeks of treatment for each patient. Tolerability and safety of the product were also evaluated. RESULTS: Twenty-five female patients with a median age of 23.4 were enrolled. Twenty-two (88%) completed the 2-month treatment period visits. At baseline the total acne lesion number, mean (SD), was 5.5 (4) and the GAG score 9 (4). A significant (P=0.001) reduction in number of total acne lesions was observed at week 4 (-57%) and at week 8 (-80%). All patients presented a significant reduction of the GAGS score values: -42% at week 4 and -78% at week 8, confirming the clinical efficacy of the product. At baseline TEWL was 10.2 g/m2/h (1.3) and 10.7 (1.4) at week 8, thus showing that the gel did not impair the skin barrier function. Skin colorimetry was significantly (P=0.0015) reduced by the treatment in comparison with baseline (62 vs. 58). Efficacy of the gel formulation was also confirmed with RCM exams, showing a reduction of dermal inflammation and exocytosis, and an improvement of infundibular hyperkeratinization. We observed that adherence to treatment correlated positively with the improvement of the single parameters. Moreover, side effects such as erythema, dryness, and excessive xerosis were not reported, resulting in a complete adherence to the treatment. CONCLUSIONS: Our findings provide favorable evidences of the efficacy and safety of this new product as a first line treatment in patients with mild acne, or, as a maintenance therapy for prolonged periods after the suspension of a systemic treatment. Furthermore, the tolerability of this topical product and the absence of any side effects increased the adherence to the therapy.