Preparation And Performance Of Chitosan-Based Controlled Release Material

Firstly,chitosan,gelatin and sodium hyaluronate were used as raw material,Na2SO4 was used as crosslinking agent,through the tape casting method and freeze drying technology to prepare the porous membrane.The surface morphology and structural of chitosan,gelatin,sodium hyaluronate,drugs-loaded membrane,uncross-linked and cross-linked porous membrane analysised by scanning electron microscope(SEM),fourier transform infrared spectrometer(FT-IR)and X-ray diffraction analyzer(XRD).The cytotoxicity was studied by MTT assay,and we have investigated the release characteristics to make an extended-release preparation for levofloxacin hydrochloride.In addition,the content of each component,pH,freezing temperature on the mechanical properties of the composite membrane,thickness,water absorption rate,apparent porosity and degradation rate affected the properties of porous membranes.When chitosan content was 2%,gelatin content of 0.4%,sodium hyaluronate content of 0.3%,pH of 5,freezing temperature of-30?,the comprehensive performance of composite membrane was best.The average tensile strength was 47.34MPa and average elongation at break was 13.45%,the water absorption of membrance was 165%,the apparent porosity was 84%,the degradation rate was 85%.Chitosan had higher crystallinity,gelatin and sodium hyaluronate exhibited amorphous form.The surface of the membrane prepared by blast drying technology was dense and smooth.The internal connectivity of the porous membrane was good by freeze drying technology.There were a large number of hydrogen bonding among chitosan,gelatin and sodium hyaluronate.The degree of crystallinity of porous membrane increased significantly after cross-linking treatment and produced strong electrostatic attraction.Toxocity of the porous membrance was zero order reaction,and exhibited good biological activity.Drugs-loaded membrances were prepared through five drug concentration in the solution.SEM,XRD and IR were applied to investigate the structure and releasing effects of drug was also tested by a simulation method of released test in vitro.The results were as follows:The drug loading was 21%and drug loading efficiency was 67%when the drug concentration was 5g/L.A large number of hydrogen bonding formed between levofloxacin hydrochloride and components.Most of the characteristic diffraction peak in the containing membrane disappearanced or weakened,and easier containing drug released.The releasing effects of containing membrane was firs-order kinetics-ln(1-Q)=-0.05194t-0.30579.The drug release was mainly diffusion within 24 hours,after a period of time by erosion,relaxation and other factors.