Preparation And Study Of Chitosan/Ferulic Acid Copolymer And Its Sustained Release Material

Natural polymer polysaccharides have been used in pharmaceutical formulations,causing a great deal of attention in various fields of scholars.Study the application of polysaccharides in drug release system has become a hot spot.It is hoped that polysaccharide will be used as carrier to realize the slow release of drugs and be heavily absorbed.It was also can improve the absorption and utilization of drug.At present,more and more researchs about chitosan as a drug carrier material,which is a natural polycation polysaccharide.The chemical name of chitosan is Polyglucosamine(1-4)-2-amino-B-D-glucose.The precursor of chitosan is chitin,which is widely present in nature.chitosan is obtained by deacetylation of chitin.The structure of chitosan is unique.There are many functional groups on the molecule of chitosan,such as carboxyl group and hydroxyl group.The chitosan can be modified by modifying the functional group to obtain the multifunctional derivative.In addition,chitosan has good biocompatibility,showing the interaction of the organization;it also has the ability of microbiological degradation,mainly because of the molecular bonds of chitosan were broken up and degradated under the action of some enzymes;chitosan is safe and non-toxic,which is one of the key areas of concern by many scholars in various fields.All above these structures and characteristics of chitosan become the focus of scholars from all walks of life.In the food industry,chitosan can be mainly used to make mainly edible film;In medicine,it is treated as antibacterial materials.In addition to breakthrough.However,chitosan also has its own shortcomings,such as poor that,chitosan was widely applied in the environmental health,biomedical engineering,chemical and cosmetics and other fields and have a major water solubility,it is only dissolve in the dilute acid solution and almost insoluble in neutral and alkaline solution,which to some extent limits the scope of application of chitosan.The key to this study is the introduction of the hydrophilic functional group-CH=CHCOOH to the chitosan structural unit,so that the functional group-CH=CHCOOH reacts with-NH2 on the chitosan molecule to produce a polymer,which have excellent properties.And then according to the characteristics and properties of the polymer,we prepared drug-loaded microcapsule materials,which not only expanding the scope of application of chitosan,but also lay the foundation for further research in this field.The chitosan/ferulic polymer was prepared by cross-linking method.The effect of synthesis conditions on the grafting degree of the polymer was discussed to choose the optimum conditions for preparing the polymer.The structure and properties were characterized by UV-Vis,IR,X-ray diffraction,scanning electron microscopy(SEM)and thermal stability analysis.The results showed that flaky structure of chitosan was destroyed and the porous structure was formed.The stability of chitosan/ferulic was enhanced compared with that of chitosan,and the crystallinity is decreased.The optimum reaction conditions were as follows:mass ratio of CS to FA was 1:1,and reaction temperature was 60?,reaction time was 3h.In this condition the highest content of phenol group and the highest degree of substitution were obtained.After polymerization,the swelling property is improved,which provides powerful conditions for the controlled release.In order to optimize the structure and performance characteristics of the polymer,the free radical-mediated was used to prepare the chitosan/ferulic.FTIR,SEM,XRD and TGA were used to study the structure and properties of the polymer.The results showed that Chitosan and ferulic acid had a chemical reaction and formed a polymer,which is a non-crystalline material with a porous structure.Compared with the polymer prepared by cross-linked method,the stability and swelling were better.The optimum reaction conditions were determined as follows:mass ratio of CS to FA was 1:1,and reaction temperature was 30?,and reaction time was 24 h.Preparation of chitosan/ferulic loaded drug microspheres based on spray drying.The average particle size and drug loading as evaluation index to evaluate the optimized formula.The size and morphology of the microspheres were analyzed by laser particle size analyzer and SEM.The structure and properties of the microspheres were characterized by TGA,DSC and X-ray diffraction.It was found that the size distribution of drug-loaded microspheres was 4?7?m and the average diameter was 4.53 ?m.The dispersion of the microspheres is good,and the size of the microspheres is uniform,and the spheres are less agglomerated.At the same time,SEM micrographs showed that the surface morphology of the microspheres was changed after drug loading,and some of the drugs were adsorbed on the microcapsules.In pH 7.4 phosphate buffered solution,the release behavior of chitosan/ferulic drug-loaded microspheres showed that the drug were slow to release from microspheres without burst release,and the drug release was up to 15 hours.The cumulative release rates were 72.009%.The in vitro release behavior of drug-loaded microspheres was fitted by five common empirical models by establishing the model of drug release kinetics.The model was evaluated by the Akaiichi Information Criterion(AIC)under the complex conditions of model fitting and parameter introduction.The results showed that the dissolution model had the best fitting effect on the release of BSA,which could reflect the actual drug release law.