The Study Of Blood Volume Expansion Agent Hydroxyethyl Starch 130/0.4

Hydroxyethyl starch 130/0.4,as the latest generation of blood volume expansion agent,plays a unique role in increasing blood volume and improving body microcirculation.It is a starch derivative obtained from amylopectin corn starch via acid hydrolysis and hydroxyethylated reaction with ethylene oxide or ethylene glycol as etherification agent under alkaline conditions.This article reports a detailed study of the production process of hydroxyethyl starch 130/0.4,the main contents are as follows:Firstly,corn starch is being hydrolyzed,resulting in a drop of its molecular weight to within a certain range.The starch slurry concentration,hydrolysis temperature and the concentration of hydrochloric acid of this inorganic acid hydrolysis process will be explicitly discussed.The experimental results revealed that hydrolysis temperature is the maximum impact factor of the hydrolysis reaction if the concentration of starch slurry is fixed;and the optimum hydrolysis temperature and acid concentration is 75? and 0.05mol/L respectively.The study also shows that there is a linear relationship between the movement viscosity of starch solution and the average molecular weight of the final product.In this article,sodium hydroxide acts as a catalyst while ethylene oxide acts as etherification agent in this study.The impact of reaction temperature,reaction time,the amount of sodium hydroxide and ethylene oxide on the degree of substitution and substituted position of the product was examined in detail.The orthogonal experiment results show that the amount of ethylene oxide is the biggest factor affecting the degree of substitution;and the alkali dosage has the biggest impact on the substitution position.Finally,by repeated experiments,we determined the optimum process for the synthesis of hydroxyethyl starch 130.Then,the refining process of hydroxyethyl starch 130/0.4 was reported in detail,by varying different factors in bleaching,ultrafiltration and electrodialysis conditions,we ultimately determined that the best conditions of the refining process,which is,1)high temperature bleaching under 60?,while maintaining pH between 7 to 9 during the decolorization process;2)seven times of ultrafiltration under room temperature with PES ultrafiltration membrane with MWCO around 50 000,with the same amount of pure water diluting the concentrate after each time of ultrafiltration;3)electrodialysis desalination under operating voltage of 15 V,and keeping the circulation flow at 80L/h,after 0.5h of desalination,the salt content of the product is reduced to less than 0.3%.Finally,we analyzed the hydroxyethyl starch 130/0.4 that we obtained via nuclear magnetic resonance and infrared spectroscopy.Comparative analysis of the results show that the product we obtained possess the same structure as the German samples.We also conducted product quality tests which revealed that all factors of the subject product indicate that it meets the corresponding requirements,referencing to the European pharmacopoeia standards.