Optimization on preparation of Saussureae Involucratar Herba extract-composite phospholipid liposome by central composite design-response surface method Preparation and stability of sub-micro-emulsion of which the emulsifier is digalactosyl diglyceride from natural product Preparation and stability of digalactosyl diglyceride as emulsifier forsub-microemulsion Preparation of glycyrrhetinic acid niosomes and optimization of its prescription process Optimization on formulation of microporosity osmotic pump controlled release tablet of solid dispersion for total flavonoids from Desmodium styracifolium by central composite design-response surface methodology