Construction of various lipid carriers to study the transdermal penetration mechanism of sinomenine hydrochloride

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.