Objective: To prepare an appropriate puerarin-loaded nanostructured lipid carriers(Pue-NLC) for brain targeted drug delivery

and investigate its physicochemical properties and in vitro release. Method: Pue-NLC was prepared by emulsion-ultrasonic dispersion method.With encapsulation efficiency as index

single factor test and orthogonal test was adopted to optimize preparation technology with the amount of solid lipid material

ratio of soybean lecithin and poloxamer-188

ratio of lipid material and emulsifier

the amount of drug as factors;Particle morphology of dispersion was observed by transmission electron microscopy

surface potential and particle size were determined by Zeta potential and particle size analyzer

entrapment efficiency was determined by centrifugation ultrafiltration method.In vitro drug release behavior was studied by dialysis

the content of puerarin was determined by HPLC. Result: Optimum preparation technology was as following:the dosage of solid lipid material 400 mg

ratio of soybean lecithin and poloxamer-188=1:3

ratio of lipid material and emulsifier 1:2

the amount of drug 10 mg.Under transmission electronic microscope

Pue-NLC assumed spherical shape. Its distribution of particle size was even with the average value of (89±7) nm.Entrapment efficiency was (91.33±1.2)%.The average Zeta potential was (-22±0.4) mV;Cumulative release of puerarin was 69.25% in 24 h without burst effect. Conclusion: These prepared Pue-NLC had uniform particle size distribution

high encapsulation efficiency

sustained release effect.