Purpose: To clarify the inner framework and relative properties in vitro of Lyotropic liquid
crystal (LLC) based on various prescriptions by using hydrophilic sinomenine hydrochloride (SH) and
lipophilic cinnamaldehyde (CA) as model drugs.
Methods: Phase structures were checked by polarized light microscopy (PLM) and small-angle X-ray
scattering (SAXS). Rheological studies and Attenuated Total Reflectance Fourier Transform Infrared
(ATR-FTIR) analysis were carried out to reveal their molecular interactions. In vitro release and skin
permeation were conducted by Franz diffusion cell.
Results: PLM and SAXS showed double diamond cubic crystal. All the samples displayed characteristics
of non-Newtonian fluid, and the molecular interactions increased with the reducing water. ATRFTIR
showed that the strongest strength of hydrogen bond emerged in the formulation with 32% water.
Released SH of S2 and S3 arrived over 80%, while S1 only reached 45%, and that of CA was about
23%. Water-rich prescription gave higher percutaneous penetration for hydrophilic drugs, whereas no
significant difference existed in CA permeation.
Conclusion: Proportion of Phytantriol to water determined the LLC assembling and affected the
dissolving status of hydrophilic substance, thereby impacting on the location sites of guest molecular
interactions among the substances, rheology properties, and finally the release and penetration behavior
in vitro. Adjusting the basic prescription was the key to obtain satisfactory percutaneous delivery and
stability for LLC carrying multi-therapeutic agents.