Core-shell-type polymer-lipid nanoparticles for the transdermal delivery of daidzein

Daidzein (DZ) is an ideal Chinese herb for treating cardiocerebrovascular disease. Despite its poor water solubility and limited application, DZ was successfully loaded, along with penetration enhancer azone, onto core-shell-type polymer-lipid nanoparticles through a two-step preparation method. The mean particle diameter, encapsulation efficiency, and drug-loading rate of DZ-polymer-azone-lipid nanoparticles (D-P-Azone-LNs) were 77.59 +/- 2.26 nm, 79.91% +/- 1.46%, and 1.50% +/- 0.02%, respectively. In skin penetration experiment, the cumulative amount of DZ from D-P-Azone-LN reached 14.91 g cm( -2) at 72 h. This amount was 1.44 and 6.01 times higher than those of DZ-polymer-lipid nanoparticles (D-P-LNs) and DZ solution, respectively. Confocal laser scanning microscopy was used to conduct a qualitative analysis. In vivo study, D-P-Azone-LN achieved better skin retention than those of D-P-LN and DZ. Furthermore, no significant irritation was observed in the skin irritation experiment. These results suggested that the core-shell polymer-lipid nanoparticles, which combined the properties of polymer and lipid nanoparticles, can offer a useful formulation for enhancing the skin permeation of drug for transdermal delivery.