Phase transition and release kinetics of polyphenols encapsulated lyotropic liquid crystals.

In this paper, the lyotropic liquid crystals formed in SL/IP/H2O system were prepared as a drug carrier system to encapsulate polyphenols. The components and introduction of drug had influences in the structure and rheological properties of lyotropic liquid crystals. The structure underwent a phase transition from lamellar phase (Lα) to Lα + HII (reverse hexagonal phase) mixed phases and micelle by increasing its IP/H2O mass ratio from 5/35 to 20/20 and 35/5, consistent with the transition from solid-like properties to viscous fluid properties. For the Lα + HII phase, the loading of DMY induced the structural transition to the HII phase, confirmed by SAXS results. This may be due to the penetration of DMY into the hydrophobic tails of surfactants. The in vitro release kinetic resulted that the release of drug in Lα was associated with diffusional mass transport and matrix swelling. While the release behavior of DMY in HII phase was predominantly controlled by concentration diffusion. These relationships among structure, rheology and release kinetics should be conductive to further design the drug sustained carrier system formed by lyotropic liquid crystals.