Objective To investigate the transdermal mechanisms and compare the differences in transdermal delivery of Sinomenine hydrochloride (SN) between solid lipid nanoparticles (SLN), liposomes (LS), and nanoemulsions (NE).Methods SN-SLN, SN-LS and SN-NE were prepared by ultrasound, ethanol injection and spontaneous emulsification, respectively. FTIR, DSC, in vitro skin penetration, activation energy (Ea) analysis were used to explore the mechanism of drug penetration across the skin.Results The particle size and encapsulation efficiency were 126.60 nm, 43.23 ± 0.48%(w/w) for SN-SLN, 224.90 nm, 78.31 ± 0.75%(w/w) for SN-LS, and 83.22 nm, 89.01 ± 2.16%(w/w) for SN-LS. FTIR and DSC showed the preparations had various levels of impacts on the stratum corneum’s lipid structure which was in the order of SLN > NE > LS. Ea values of SN-SLN, SN-LS, and SN-NE crossing the skin were 2.504, 1.161, and 2.510 kcal/mol, respectively.Conclusion SLN had a greater degree of alteration on the skin cuticle, which allows SN to permeate skin more effectively.
The goal of this paper was to develop and evaluate dual component-loaded with the hydrophilic sinomenine hydrochloride (SH) and lipophilic cinnamaldehyde (CA) cubic liquid crystal gels for transdermal delivery. The gels was prepared with a vortex method using phytantriol/water (70:30, w/w) and characterized by polarized light microscopy, small-angle X-ray scattering and rheology. The inner structure of the gels were Pn3m cubic phase and exhibited a pseudoplastic fluid behavior. Furthermore, the in vitro release profile showed that the release behavior of the two drugs from cubic liquid crystal gels conformed to Higuchi equation and were dominated by Fick’s diffusion (n < 0.45). The ex vivo penetration experiment indicated that dual components-loaded liquid crystal gels can enhance and extend the skin permeation of these two drugs, especially the ratio of SH to CA is 1: 0.5. Finally, transdermal mechanisms were evaluated using laser scanning confocal microscopy and attenuated total reflectance-fourier transform infrared, hinting that hydrophilic and lipophilic drugs weaken each other’s transdermal velocity at the initial stage of penetration. In short, the dual drug-loaded liquid crystal gels was a promising strategy for transdermal applications in treatment of chronic disease.