Application Of Penetrable Silica Microspheres In Immobilized Liposome Chromatography And Semi-Preparative Hydrophilic Interaction Chromatography

Penetrable silica microspheres possessed mesopores and penetrable macropores, which afforded sufficient surface area and fast mass transfer, respectively. Based on this special property, the silica was successfully applied as the stationary phase matrix in immobilized liposome chromatography (ILC) and semi-preparative hydrophilic interaction chromatography (HILIC).(1) An immobilized liposome chromatography (ILC) stationary phase based on penetrable silica microspheres was prepared. Compared with the ILC column based on common porous silica gels, the penetrable silica had larger capacity for liposomes’ immobilization, lower backpressure and higher separation efficiency. Twenty-two drugs were used as tested analytes and their retention behaviors on newly prepared ILC column were investigated in detail. Column temperature and pH of mobile phase were both key factors affecting the retention of solutes. The retention of these drugs on ILC column reflected their permeability in vivo. Furthermore, the methanolic aqueous extracts of three traditional Chinese medicines (TCMs), Radix Liquiritiae, Scutellaria baicalensis and Flos Sophorae, were screened on this novel ILC column. Effects of column temperature and eluent pH on chromatographic behaviors of components of the TCM methanolic extracts were also studied. Several permeable components could be found, indicating that they are potentially active components in the TCMs. It was also found that the as-prepared ILC column remained stable in at least1month and the relative standard deviations of retention time for solutes were lower than9.0%. The proposed ILC based on the penetrable silica microspheres is promising for the fast and low-pressure separation, especially for fast screening of permeable compounds and modeling the drug-membrane interaction in vitro.(2) Crude phosphatidylcholine (PC) was extracted with ethanol from egg yolk, and an L9(34) orthogonal array experimental design was set up to optimize the solvent extraction conditions. Subsequently, semi-preparative hydrophilic interaction chromatography (HILIC) based on penetrable silica microspheres was explored to purify the crude extract on homemade silica column. The purity of PC prepared in this way can reach up to93.96%with the fast separation.