The Investigations of Construction and in vitro Release of Curcumin Lyotropic Liquid Crystals: Phase Diagrams, Small Angle X‐ray Scattering, Rheological Technology, and Release Kinetics

Abstract

In this study, hexagonal and cubic lyotropic liquid crystals (LLC) were constructed in Brij 97‐Tween 40 (MS82, MS64 and MS46)/OLA/H2O systems to encapsulate curcumin. MS82, MS64, and MS46 indicated that the mass ratio of Brij 97/Tween 40 was 8/2, 6/4, and 4/6. The microstructure of curcumin LLC was studied using small angle X‐ray scattering (SAXS). Phase diagrams showed that the increase of MS reduced the phase transition temperature (TC). Particularly, the TC of sample C1Cur [Brij 97‐Tween 40 (MS46)/OLA/H2O = 50.0/2.8/47.2] and C2Cur [Brij 97‐Tween 40 (MS46)/OLA/H2O = 50.0/25.0/25.0] was 37.6 and 35.4 °C, respectively, close to the temperature of the human body. Thus, the shear rheology and SAXS were used to study the structural changes of samples C1Cur and C2Cur with temperature. The moduli values of samples C1Cur and C2Cur decreased with the increase of temperature, showing various structural strengths. in vitro release experiment was used to study the drug release kinetics. The release of curcumin from LLC conformed to the concentration diffusion model. Due to a similar aS, the release of curcumin from samples A1Cur, B1Cur, and C1Cur (Brij 97‐Tween 40/OLA/H2O = 50.0/2.8/47.2 and the MS is MS82, MS64, and MS46) showed a similar release behavior under different MS. The release behavior of curcumin was related to the structure of samples C1Cur and C2Cur at different temperatures. Curcumin exhibited the fastest release rate when the samples behaved as the micellar phase.