Lipid- and Polymer-Based Nanostructures for Cutaneous Delivery of Curcumin

It is well-known that nanoencapsulation may overcome biopharmaceutical limitations of curcumin (CUR), but studies regarding the contribution of the vesicular nature of CUR-loaded nanoparticles on skin permeation are still scarce. Therefore, the effect of three colloidal systems (solid lipid nanoparticles (SLN), nanoemulsion (NE), and polymeric nanoparticles (NP)) on the control of cutaneous permeation of CUR was investigated in porcine ear skin/Franz diffusion cells. Colloidal suspensions were designed to present a similar particle size (+/- 170 nm), narrow size distribution (PdI < 0.2), and high entrapment efficiency (>99%). Zeta potential values were -0.13, -9.68 and -36.7 mV for the CUR-loaded NP, SLN and NE, respectively. Nanoencapsulation resulted in a cumulative amount of CUR in the more superficial layers of the skin. NP significantly enhanced the compound retention in the epidermis, which was approximately 2.49- and 3.32-fold more than SLN and NE, respectively. The CUR levels into the dermis were significantly increased after treatment with NE, which may be associated with repulsion phenomena in surface skin. Therefore, a more superficial or deeper action of CUR on the skin may be obtained depending on nanostructure type. While NPs are more effective in upper skin layers, NE should be prioritized when a dermal action for the CUR is required.