Superoxide Dismutase Preparation Of Gelatin Microspheres With Surface Chemical Modification

Superoxide dismutase (SOD) is an important scanvenger of reactive oxygen radicals, which can be used to treat or prevent radical-related diseases. Nowadays, SOD is used mainly as injection clinically, while oral formulation for SOD is less investigated. In this work, SOD gelatin microspheres were made with the aim to improve its stability, oral relative bioavailability, and to study the preparation conditions of microspheres.First, the auto-oxidization of pyrogallol was used as the analysis method to determine SOD activity, and the precision , recovery and linear range of the method were investigated. The results showed that the method was feasible.In physical and chemical property tests, different macromolecular materials were tried to protect SOD activity, and the results showed that natural polymers, such as gelatin and alginate, were more effective in SOD activity protection than synthesized ones.In this study, SOD gelatin microspheres were prepared by emultion coagulation procedure. After single factor tests, the orthogonal design were performed to opitimize the conditions for the process. The best condition was W/O,3: 40, temperature, 60 C, time, 5 min, agitation rate, 400rpm. The microspheres thus derived had an embedding rate of 88%, a drug loading of 23200u/g, and a size mainly around 25-75 urn.We studied the rheology of alginate, its compatability with gelatin and the interfacial tension between alginate and gelatin, the molecular weight and degree of deacylation of chitosan were determined as well. On the basis of the work above,the alginate gelatin complex microparticle and the surface modified microsphereswere prepared, and the SOD embedding rate ,SOD stability and release behavior of the product were determined . The surface property of the modified microsphere were studied, too.In pharmacodynamics, the dose-response relationship of SOD in antiinflammation was studied, then the time-response property of different microspheres were investigated. The results showed that all of the microspheres could prolong the antiinflammation time in mouse.