D-limonene nanoemulsion as skin permeation enhancer for curcumin prepared by ultrasonic emulsification

Abstract

d-limonene nanoemulsion (NE) previously showed satisfactory potential for storage stability and might be a safety carrier for transdermal drug delivery systems (TDDSs). Curcumin has been widely studied for health promotion, food safety, and functions. This study evaluated the application of d-limonene NE carrier for curcumin embedding and the transdermal absorption effect. Results revealed that the droplet size of curcumin NE affected the cumulative concentration of transdermal absorption following the descending order of hydrophilic-lipophilic balance (HLB) 11 > 8 > 5 > 3 > microemulsion (p < 0.05). The droplet size was also correlated with the steady-state flux of transdermal absorption by permeability and was twice as high for HLB value 11 (84.3 nm) and HLB value 3 (384.7 nm). In addition, the cumulative concentration of HLB 11 (57.13 %) was nearly double higher than that of HLB 3 (26.29 %) (p < 0.05). The developed d-limonene-encapsulated curcumin NE has a macroscopic bioactivity, which can be retarded release by encapsulating the bioactive source, enabling it to be biomimetic simply. Therefore, the study has important implications for forming and designing encapsulated bioactive TDDS. All these findings suggested that d-limonene NE could function as a carrier for TDDS in food/cosmetic products.