Studies On Preparation And Performance Of Cassava Starch Microspheres

Cassava is a characteristics plants in hainan and it’s production of starch is more than other plants’. The use of cassava help to keep cost down. Starch cassava is made into starch micro-spheres that have very large specific surface area and rich pore structure. Due to the specialty of the starch micro-spheres, it can absorption medicine easily. Besides, they are non-toxic no immunogenicity and layer upon layer hydrolysis, so medicine can keep more time in body that accord with modern drug earner.In this thesis, oil-soluble N, N—methylene-bis-acrylamide was used as cross-linker and chloroform and cyclohexane was used as oil phase.The preparation process were investigated by single factor experiment.The optimum drug-loading conditions were determined as4.5g/L cross-linking polymerization,2g/L initiating agent,2h crosslinking time,50℃reaction temperature and suitable mixing speed. Scanning electron microscopy were used to characterize morphology of the surface. The results showed that cassava starch microspheres are spherical particulates with rules surface, size of10μm or so and N,N-methylene-bis—acrylamide appear cross linked with starch lead to starch’s degree of crystalline decreased after microspheres were reacted. In addition water-soluble sodium trimetaphosphate was used as cross-linker and coconut oil as oil phase to find best preparation technology. The optimum drug-loading conditions were determined as3%cross-linking polymerization,4%emulsifier,11pH value,5%starch solution concentration and5h crosslinking time. After characterization found that cassava starch microspheres are rough and holes with rules surface,20μm particles and starch’s degree of heat resistance increased when crystalline decreased.The degradation property of cassava starch microspheres was researched after successful preparation of the starch microspheres.47.31%cassava starch microspheres was degradated by measured the concentration of glucose. In the first three hours, degradation was slow and the micro-spheres was structure densified. But after three hours, degradation was very noticeable.The structure of micro-spheres become loose and it’s particle size decreased rapidly. The cassava starch microsphe-res can be disintegrated to release drug locatedly when they reach colon after going through the alimentary canal according to operation3to6hours. Thus the preparation of cassava starch microspheres are expected to be the ideal drug carrier of TBDE and OCDDS.