Pore-forming Methods Of The Corn Starch Microspheres And The Study Of Their Application Performance

Starch microspheres are polymer microspheres, which can be used in drug loading and spice absorbing.Three sodium metaphosphate crosslinked starch microspheres are anionic starch microspheres, which has a strong adsorption of cationic drug.This article uses three sodium metaphosphate as crosslinking agent to prepare starch microspheres.Porous starch microsphere improved the performance of starch microspheres, compared with starch microspheres,porous starch microspheres have the higher porosity,and their quality are lighter,so porous starch microspheres had better adsorption performance and faster diffusion speed.They can quickly reach the adsorption equilibrium.This paper investigates the method of preparation of porous microspheres.In this paper, we used corn starch as raw materials, three partial sodium phosphate as crosslinking agent, Span80 as emulsifier, soybean oil as oil phase,and prepared the starch microspheres by using inverse emulsion crosslinking method.The microspheres preparation conditions were optimized.The optimized conditions are: corn starch mass fraction is 5%,crosslinking agent dosage is 0.28 g/g, emulsifier dosage is 0.05 g/ml, oil and water phase volume ratio 3:1, mechanical agitation speed 600 r/min.These factors formed the water-in-oil inverse emulsion system.Then we observed the morphology of the microspheres by optical microscope,they are more rounded, particle size distribution is relatively uniform, average particle size is about 68 μm.On this basis, we studied the pore-forming methods.We use the method of freeze drying and adding pore-forming agent respectively.The structure of the porous microspheres were observed by scanning electron microscope and we studied the effect of different PEG6000 adding amount on the porosity of microspheres.With methylene blue as modle drugs, drug load performance of the porous microspheres were studied, and we compared the drug delivery ability of different microspheres prepared by different pore-forming methods. When the PEG6000 content was 30%, the porosity of porous microspheres was 89%, the drug loading content is 158 mg/g.And then we examined the effect of drug concentration, loadingtime and loading temperature on the adsorption.The optimized conditions are: drug concentration is 750 mg/L, loading time is 3 h, loading temperature is 25 ℃.Then used the porous corn starch microspheres to adsorb the rosemary essential oil and discussed the influence of various factors on the adsorption performance, when the volume fraction of the rosemary essential oil is 6% and adsorption time is 2 hours, the microspheres have a better adsorption capacity and adsorption efficiency at the same time.