Background: There has been a growing concern in transdermal drug technology over the past
several decades. As a novel transdermal delivery system, Lyotropic liquid crystals (LLC) still face challenges
such as drug loading, limited drug permeation and instability of systems. LLC system is so sensitive
that a very subtle change in composition may induce a phase transformation or conversion of spatial
configuration, and result in a diverse percutaneous delivery subsequently.
Objective: To find out the effects of hydrophilic and lipophilic components on the structure and transdermal
properties of LLCs, hydrophilic sinomenine hydrochloride (SH) and lipophilic cinnamaldehyde
(CA) was chosen as a model drug and a skin permeation enhancer, respectively, several formulations
were prepared and compared.
Method: The structure of LLC was evaluated by visual observation, Cross-polarizing light microscopy
(CPLM) and Small angle X-ray diffraction (SAXS). The Franz diffusion cell was applied to investigate
its skin penetration of SH across the rat skins. Fourier transform infrared spectroscopy (FTIR) was recorded
to evaluate the intermolecular interaction between the LC samples and stratum corneum (SC).
Conclusion: The results showed that a controlled transdermal process might be obtained by adjusting the
ratios of different drugs or loading doses when LLCs with dual-components were applied.