Study On Extraction And Purification Of Schisandrin And Preparation Of Nanostructured Lipid Carrier

Schisandrin is the main active ingredient in Schisandraceae,which is distributed mainly in Schisandra chinensis.Schisandrin possesses some pharmacological activities,including sedative hypnosis,protecting brain neurons,enhancing the function of learning and memory,and has a good therapeutic effect on brain diseases.As far more research of schisandrin is focused on its pharmacological activity,and less studied on its dosage form,and no suitable product has been seen in the market.The main reason is due to its poor water solubility and low bioavailability.Therefore,this paper will carry out the following research:Identification of Schisandra sphenanthera and Schisandra chinensis: electronic nose and electronic tongue technology were used to detect the smell and taste of the samples from different regions.Principal component analysis(PCA)and discriminant factor analysis(DFA)and other chemometrics methods were used to analyze the the acquired characteristic data.The results showed that the electronic nose combined with DFA,electronic tongue combined with PCA or DFA can successfully distinguish between Schisandra sphenanthera and Schisandra chinensis,and the correct classification rate reached 100%.Optimization of extraction technology of Schisandrin: taken schisandrin as the evaluation index,a single factor test and response surface methodology were used to optimize the extraction process of schisandrin by ultrasonic extraction technology.The best conditions were as follows: ethanol concentration 81%,extraction temperature 40?,material to liquid ratio 1:10,and extraction time 14 min.Under this optimum condition,the maximum extraction yield of schisandrin was 0.59%.Optimization of the purification process of schisandrin: macroporous resin AB-8was selected to optimize the purification process of schisandrin by measuring the adsorption ratio eluting ratio of schisandrin.The optimum purification conditions were as follows: 0.06 g/mL sample concentration,1 mL/min flow rate,160 mLsample volume,2 BV deionized water is washed,and 80% ethanol is eluted with 2mL/min flow rate.Under this optimum condition,the maximum yield of schisandrin is 94.51% and the purity is 46.54%.Study on schisandrin nanostructured lipid carriers(SCH-NLC): SCH-NLC were prepared by the melt ultrasonication method with using glycerin monostearate(GMS)and medium chain triglycerides(MCT)as solid and liquid lipids,respectively,and poloxamer-188 as the emulsifier.The formulation and process was optimized with the index of particle size and entrapment efficiency,and the freeze-dried technics was further optimized.The optimal formulation and process were as follows: emulsifier concentration was 3.8%,mixed lipid concentration of 4%,which accounted for23.51% of liquid lipid,SCH/Lipids ratio 1:20,emulsification temperature was 75?,stirring time was 10 min,stirring speed of 900 r/min,ultrasonic time was 10 min,ultrasonic amplitude was 100%,cryoprotector was 10% trehalose.Under this optimum condition,the SCH-NLC nanoparticles prepared were sphere-like.The average particle size,entrapment efficacy and drug loading were(94.11±4.09)nm,(89.13±0.38)% and(2.34±0.07)%,respectively.XRD analysis showed that the SCH encapsulated in NLC was in the amorphous form.The in vitro release experiments studied showed that the SCH-NLC had good sustained-release characteristics in 24 h.