RESUMEN
AIM To prepare andrographolide self-microemulsifying drug delivery system.METHODS The range of excipient ratio was determined according to equilibrium solubility,excipient compatibility and pseudo-ternary phase diagram.With Pogostemon cablin oil proportion,Labrasol ALF-Tween 80 ratio and Km as influencing factors,drug loading as an evaluation index,the formulation was optimized by central composite design-response surface method,after which in vitro evaluation was performed.RESULTS The optimized formulation was determined to be 10.45%,13.28%,9.82%,66.44%for Pogostemon cablin oil,Labrasol ALF,Tween 80,Transcutol HP proportions,the equilibrium solubility was(11.95±0.04)mg/g.The quality parameters were(20.22±0.38)s for emulsification time,(51.70±2.91)nm for particle size,0.27±0.02 for polydispersity index,and(91.21±1.58)%for light transmission rate,respectively.The self-microemulsion drug delivery system demonstrated good freeze-thaw stability,whose particle size was not obviously influenced by dilution times and dispersion medium,and was rapidly dissolved in phosphate buffer solution(pH 6.8).CONCLUSION Self-microemulsifying drug delivery system can enhance the solubility and dissolution rate of andrographolide.