Preparation Of Nanopalygorskite Euryale Ferox Starch Microspheres And Its Drug Loading Property

This article first used euryale ferox as raw material,the starch was modified by wet ball-milling,and discussed the effect of wet ball-milling on the physicochemical properties such as euryale ferox starch particle size,amylose content,crystallinity,etc.Subsequently,attapulgite clay-euryale ferox starch(compound)microspheres by spray drying were prepared,and then the effects of spray drying air inlet temperature,creep speed,starch concentration,mass ratio of attapulgite clay to starch on the formation of microspheres were investigated.Finally,curcumin is taken as the drug delivery model to study the adsorption and drug delivery characteristics of composite microspheres and euryale ferox starch microspheres.The main conclusions are as follows:(1)The starch granule morphology,crystals and amylose content of euryale ferox powder and euryale ferox starch after ball-milling have changed.By comparison,the starch granules were more likely to be damaged after direct ball-milling,and the changes in crystallinity and amylose content were more prominent.The results showed that the ball-milling treatment can increase the amylose content,which was most obvious when the ball-milling is performed for60 minutes.The ball milling treatment changes the crystallinity of the starch,which changes the most when the ball-milling is performed for 180 minutes.Andat this time,the crystal diffraction peak weakened,and the crystallinity decreased from 41.19% of the original starch to 17.54%.(2)Based on the morphology,moisture content and yield of the euryale ferox starch microspheres as the evaluation indicators,the preparation conditions of the microspheres were preliminarily screened.The suitable starch concentration was determined to be 1.5-2.5%,the mass ratio of attapulgite to starch was 1:25-1:10,air inlet temperature was 120-150?,and the creep speed was in the range from 8-12 rpm.(3)Using curcumin as drug loading model,drug-loaded composite microspheres were prepared by adsorption method.Taking the drug loading as the evaluation index,the spray drying experiment conditions were optimized by single factor,and the best composite microsphere prescription was selected.The best experimental conditions were as follows: the concentration of starch solution was2%,the mass ratio of attapulgite to starch was 1:15,the air inlet temperature was140?,the creep speed was 8 rpm.Under this condition,the drug loading was as high as 10.99 mg/g.(4)During the in vitro dissolution experiment of drug-loaded composite microsphere,in spite of the phenomenon of sudden release,the sustained release effect was more obvious.The cumulative release rate reached 89.5% in 8h,and its slow-release effect was better than drug-loaded starch microsphere.