RESUMO
Objective To prepare the supersaturation self-emulsifying drug delivery system(S-SEDDS) containing silymarin and to evaluate its basic properties.Methods With the time of self-emulsifying,the consequence of color visual examination and particle size as parameters,the optimum formulations of silymarin SSEDDS were screened by solubility test,compatibility tests and pseudo ternary phase diagrams.The silymarin concentration was determined by HPLC.The in vitro dissolution characteristics of silymarin S-SEDDS were investigated with silymarin SEDDS as control.Results The optimum silymarin S-SEDDS was composed of medium chain triglycerides(MCT) 40%,Cremophor RH40(ethoxylated hydrogenatedcastor oil) 48%,Labrasol 12%.The time of self-emulsifying was less than 3 min,the average particle diameter was 49.6 nm,the adding amount of hydroxypropyl methylcellulose(HPMC) was 50 mg/g,and the average content of silymarin was 39.3 mg/g.The in vitro dissolution test of silymarin S-SEDDS showed that the presence of a small amount of cellulosic polymer effectively sustained a metastable supersaturated state by retarding precipitation kinetics.Conclusion The designed formulation of silymarin S-SEDDS is reasonable and provides a strong foundation for further development of new preparations.