Preparation Of Two Kinds Of Esterified Starch And Study On Their Release In Drug

The preparation technology of octenyl succinic starch ester and hydroxypropyl acetylated starch adipate by using cassava starch as the raw material in the aqueous phase are studied, and their basic properties and the applications in the drug release are researched, too.First of all, the preparation technology of octenyl succinic starch ester is studied in the aqueous phase. Through the single factor experiment, the best preparation technology of octenyl succinic starch ester is researched from five aspects—the pH of the sty stem, reaction temperature, reaction time and acid anhydride concentration. The best conditions are:starch milk is35%, pH is8.5, reaction temperature is35℃, reaction time is3.5h, acid anhydride addiction is4%。With the best conditions, the degree substitution of octenyl succinic starch ester is0.02.Second, the aqueous phase method of manufacturing hydroxypropyl acetylated starch adipate is studied. Through the single factor experiments, the starch milk, ph, reaction time and mixed acid anhydride addition are studied for their influence on substitution degree. Through the orthogonal test, the best preparation technology is confirmed:starch milk is30%, pH is8.0, reaction time is1.5h, mixed anhydride content is4.5%. With the best conditions, the degree substitution of the production is0.033. According to the hydroxypropyl starch and acetylated starch adipate, under the optimum preparation technology of hydroxypropyl acetylated starch adipate, the degree substitution of hydroxypropyl is0.1264, carboxyl substitution degree is0.031.Besides, the properties of the octenyl succinic starch ester and hydroxypropyl acetylated starch adipate are compared, emphasizing to investigate the retrogradation, freeze-thaw stability, transparency and solubility of the Cassava modified starch. And the constitution of the Cassava modified starch through the modern analysis methods is analyzed:Infrared spectrogram shows that after the starch being modified, some hydroxide radical is replaced. Moreover, differential scanning calorimetry shows that the gelatinization point has changed.Finally, the applications of the modified starch in the drug release are investigated. Microspheres of modified starch are studied in the drug release process.The results indicated that the process of drug release appears first quick then slow trend and the brining in the groups of crosslinked starch can slow down or speed up the drug release rate.