Improvement of Arbutin Trans-Epidermal Delivery Using Radiofrequency Microporation

Purpose: To assess the ability of radiofrequency (RF) microporation to promote trans-epidermal delivery of arbutin.
Methods: To investigate the enhancing effect of RF microchannels on skin permeation of arbutin, in vitro skin permeability studies were performed with RF microporation-treated Hartley albino guinea pig skin using Franz diffusion cell system. Furthermore, improved depigmentation effects in brown guinea pig in vivo after treatment with RF microporation was evaluated to create hydrophilic microchannels for arbutin trans-epidermal delivery.
Results: RF microporator caused disruption of the stratum corneum (SC) and created 50 μm diameter microchannels at a depth of 100 μm in the skin. RF microporation increased skin permeability of arbutin 2.25-fold compared to untreated skin exposed to RF in vitro. Arbutin administration led to considerable skin depigmentation following RF microporation of UV-induced hyperpigmented skin in a 28-day in vivo experiment (ΔL-value on day 28: UV, 0.17 ± 0.50; UV + RF, 0.07 ± 0.48; UV + arbutin, 1.32 ± 0.51 and UV + RF + arbutin, 1.82 ± 0.53).
Conclusion: RF microporation seems to be a suitable physical trans-epidermal delivery technology for topical application of highly hydrophilic depigmentation agents through the hydrophobic skin barrier.

Keywords
Radiofrequency microporation; Trans-epidermal delivery; Depigmentation; Arbutin