RESUMEN
Objective: To improve the absorption of trifolirhizin (Tri) isolated from Sophora flavescens through preparing it to be phospholipid complex self-microemulsion. Methods: In this study, we used the silica gel column chromatography and recrystallization technology to separate and prepare trifolirhizin; And we used physical and chemical properties and spectral data to identificate the structure. We used the orthogonal experiment and the central composite design response surface method (CCD-RSM) to optimize the Tri phospholipid complex (TPC), Tri phospholipid composite material self micro-emulsifying drug delivery system (TPC-SMEDDS), and used the Caco-2 model to investigate the transmembrane transport of Tri, TPC, and TPC-SMEDDS, respectively. Results: The concentration of the phospholipid complex was 4 mg/mL, the ratio of drug to lecithin was 1:1.5, the reaction time was 3 h, the composite rate was (93.20±2.01)%. The emulsifier was polyoxyethylene castor oil (Cremphor EL40), the auxiliary emulsifier was diethylene glycol ethyl ether (Transcutol HP), and the weight ratio (Km) of phospholipid complex was 7.58. The experiments of Caco-2 cell showed that the Papp of Tri was 2.45×10-7 cm/s; The Papp values of TPC and TPC-SMEDDS were 5.13×10-6 and 1.847×10-5 cm/s, respectively. Conclusion: The permeability coefficient of Tri can be obviously improved by using phospholipid complex and self-microemulsion technique, which also can improve the efficiency of drug delivery.