Studies On The Preparation And Properties Of Zetn Microcapsules

Zein is an alcohol-soluble protein extracted from corn. The paper prepared zein microcapsules by spray drying and casting. Zein was used as the wall material and the core materials were5-fluorouracil and glucose. The zein microcapsule preparation processes, encapsulation efficiency and drug loading, the release in different environment, morphology and particle size distribution have been investigated.Zein was dissolved in80%ethanol solution. The zein microcapsules with different ratios of wall to core were prepared by the method of spray drying and casting. In the experiments5-fluorouracil and glucose were used as the core materials. The determination of zein microcapsule’s encapsulation efficiency and drug loading indicated that encapsulation efficiency and drug loading of microcapsule prepared by casting was higher. For both of the two zein microcapsule prepared by different core materials, when the wall to core was5:3, the encapsulation efficiency and drug loading was higher than other ratios. The encapsulation efficiency of zein microcapsule that added glycerol was lower than that without glycerol. The encapsulation efficiency and drug loading were the highest at80℃, when the zein microcapsule was prepared by different heating temperature. The release experiments showed that both the zein microcapsule with the core material5-fluorouracil and with glucose had a good release characteristics. In the different ratios of wall to core, when the wall to core was5:3, the drug release was higher than other ratios and the release curves of different ratios of wall to core were generally consistent. The drug release of microcapsule prepared by casting was lower than that prepared by spray drying; the drug release of zein microcapsule that added glycerol was lower than that without glycerol and the drug release of zein microcapsule in simulated gastric fluid was higher than that in simulated intestinal fluid. The SEM showed that the morphology of the zein microcapsule that added glycerol was regular spherical, and the surface was smooth; the morphology of zein microcapsule that without glycerol was irregular and the surface had ravines. The particle size determined by laser particle size analyzer showed that when the wall to core was5:3, the particle size was the largest, and the size of zein microcapsule with glycerol was smaller than that without glycerol. Experiments also found that the density of zein microcapsule with glycerol was smaller than that without glycerol. but the moisture content of zein microcapsule with glycerol was higher than that without glycerol. DSC showed that, the thermal stability of the zein microcapsule was higher, the zein microcapsule that added glycerol was more stable than that not added, the zein microcapsule prepared by spray drying was higher than that by casting.