Study On Preparation Of Chitosan Graft Copolymers And Composites Drugs Of Possessing Capabilities Of Targeted Releasing

The pharmaceutical preparation with targeted and sustained release is a kind of the orientation and the efficient release of delivery.As a new dosage,it helps to overcome the shortcomings of traditional medicines,which can meet the clinical demand better.Chitosan has been attracted much attention for its excellent antibiosis,biodegradability,biocompatibility and rich resources.Chitosan can be modified to derivatives to enhance its solubility and give it new function in order to enlarge range of applications.The paper overviewed the research progress?development dynamic and application status of chitosan grafting derivatives.The two graft copolymers were preparated and studied the loading performance of protein drugs and magnetic body,which provided experiment basis in the application of targeted and slow release drugs.The main contents and results of the paper are as follows:1.The magnetic nanoparticles Fe3O4 were prepared by reverse coprecipitation method and investigated different factors on the performance Fe304.The optimal conditions were:NH3·H2O-NH4Cl as the precipitant,nFe2+:nFe3+=1:1.5,reaction time 35?,curing temperature 60?,curing time 1.5 h.The results were:the saturation magnetization of 72.09135 emu·g-1,the coercivity of 0 Oe and the average radius of 330 nm.The Fe3O4 was characterized by FT-IR,SEM,VSM,DLS and XRD.The results showed that the Fe3O4 were of a spinel structure and superparamagnetic.2.The chitosan-g-acrylic acid copolymer was prepared with chitosan and acrylic acid under initiator.Dosage of monomer,initiator mass,reaction temperature and reaction time were investigated on the graft copolymerization.The orthogonal experiment was designed by single factor experiment and the copolymer was characterized by FT-IR,SEM and DSC.The results showed that the optimum reaction conditions were AA 3.5 ml,(NH4)2S2O8 0.25 g,reaction temperature 65 0C,reaction time 3.5 h.Under the condition the graft yield and graft efficiency of the copolymer were 702%and 96%,respectively.Structure analysis showed that the chitosan was modified with acrylic acid successfully.3.The chitosan-g-acrylamide copolymer was prepared with chitosan and acrylamide under initiator.Dosage of monomer,initiator mass,reaction temperature and reaction time were investigated on the graft copolymerization.The orthogonal experiment was designed by single factor experiment and the copolymer was characterized by FT-IR,SEM and DSC.The results showed that the optimum reaction conditions were AM 1.5 g,(NH4)2S2O8 0.2 g,reaction temperature 70 ?,reaction time 2 h.Under the condition the graft yield and graft efficiency of the copolymer were 293%and 97%,respectively.Structure analysis showed that the chitosan was modified with acrylamide successfully.4.Using gel adsorption method and low temperature grinding pressure piece of law respectively,the ternary complex was synthesized with graft copolymers,magnetic body and protein drugs to investigate the slow-release and targeted drug performance in the artificial simulation environment.The result showed that:the compound drugs preparated above were of good target under magnetic fields.The optimal reaction conditions by gel adsorption method were m(CTS-AA):m(Fe3O4):m(BCG)=2:2:1,and the drug release rate was about 80%for 25h with the saturation magnetization strength value of 40.0658 emu·g-1;The optimal reaction conditions by low temperature grinding pressure piece of law were m(CTS-AM):m(Fe3O4):m(BCG)=2:2:1,the drug release rate was about 90%for 20 h with the saturation magnetization strength value of 45.1042 emu·g-1.The terpolymer had burst release in the early 10 hours,and then entered the slow release,showing a good slow-release performance.