科研之友
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摘要
In this study, biocompatible and sustained released multiparticulate system comprising of superabsorbent copolymer (SAP) particles was prepared to reduce the local irritant effect of risedronate sodium in colon. Superabsorbent copolymers based on 2-hydroxyethyl methacrylate (HEMA), itaconic acid (IA), and polyvinyl pyrrolidone (PVP) were prepared by free radical polymerization and fractioned to form SAP particles. Ethylene glycol dimethacrylate (EGDMA) as crosslinker, potassium persulfate as initiator and N, N, N, N-tetramethylethylene diamine as activator were used. Various concentrations of polymer and monomers were used. Crosslinking was confirmed by Fourier transform infrared spectroscopy (FTIR). The dynamic swelling studies were carried out in a buffer solution of pH 1.2, 5.5, 6.5, and 7.5. Concentration of IA and pH of surrounding media showed direct relation to swelling. Gel fraction and porosity were also measured. By increasing the IA content or decreasing HEMA content, porosity increased and a direct relationship was found in the case of gel fraction with HEMA and PVP contents. Furthermore, the values of volume fraction of polymer (V2s), molecular weight between crosslinks (Mc) and solvent interaction parameters (.) were also determined. Samples were loaded with model drug risedronate sodium. In addition, drug loading efficiency was also determined which was dependent on IA and PVP contents. Drug release study was performed using buffers of pH 1.2 and 7.4. The results showed the pH dependent drug release. Drug release data were analyzed by kinetic models; zero order, first order, Higuchi and Korsemeyer-Peppas model. The release mechanism was best described by zero order kinetics at pH 1.2 and Higuchi kinetics at pH 7.4. The n value of almost all formulations was between 0.5 and 1, hence drug release followed non-Fickian release mechanism.
- 出版日期2015
