In vivo anti-melanogenesis activity and in vitro skin permeability of niacinamide-loaded flexible liposomes (Bounsphere™)

This study was conducted to evaluate preparation and characteristics of flexible liposomes (Bounsphere™) consisting of a biocompatible lipid membrane with dipotassium glycyrrhizate (DPG) as an edge activator and containing niacinamide (NA). We evaluated particle size and zeta potential of the prepared liposomes by dynamic light scattering (DLS), and investigated their deformability, safety, skin permeability, and anti-melanogenesis activity in Bounsphere™ that remained stable for more than 6 months. The average size of Bounsphere™ was about 200 nm, and the change in liposome size after 6 months was not greater than that of conventional liposomes. The zeta potential of Bounsphere™ was about 32 mV with a positive charge, indicating relatively good stability. The deformability of Bounsphere™ was higher than that of conventional liposomes. In addition, the skin permeability of Bounsphere™ was higher than that of conventional liposomes or the phosphate buffer solution. These results indicated that Bounsphere™ with DPG as an edge activator has advantages over conventional liposomes as NA carriers. Furthermore, we found that 2% NA-loaded Bounsphere™ enhanced skin whitening. Taken together, our results demonstrate that Bounsphere™ can be used as a delivery system to enhance transdermal permeation and skin whitening agent effectiveness.