The auto-gelling and drug release properties of the thermosensitive chitosan-β-glycerophosphate formulation were investigated. According to rheological study, gelation lag time of chitosan/β-glycerophosphate （GP） ...The auto-gelling and drug release properties of the thermosensitive chitosan-β-glycerophosphate formulation were investigated. According to rheological study, gelation lag time of chitosan/β-glycerophosphate （GP） solutions varied from 2 to 60min with different deacetylation degree of chitosan, pH, gelation temperature, and the particles in the sol. The gelation properties were also found to influence the release profilles of a hydrophilic drug, 5-fluorouracil （5-FU）. Morphological examination by scanning electron microphotography demonstrated that large ＂pores＂ occurred during the gel-forming process, which created hydrophilic environment and led to the rapid initial release of the drug （85% in f＇LrSt 8h）. Poly-3-hydroxybutyrate （PHB）, a biodegradable material, was applied here as scaffold to capture 5-FU into microparticles with high encapsulation efficiency by solvent-nonsolvent method. Combination of these microparticles into the chitosan-β-GP formulation could drop the rapid initial release from 85% down to 29% in the optimized PHB content （75%, by mass）. The release could sustain for about 10 months. Tiffs study provided an understanding of the potential of injectable implant using thermosensitive chitosan-β-GP formulation containing PHB based particles for the water soluble drugs that need the property of long-term delivery.展开更多
基金Supported by the National Natural Science Foundation of China (No.20376038) and the Research Foundation of the Ministry ofEducation of China (No.2002003056).
文摘The auto-gelling and drug release properties of the thermosensitive chitosan-β-glycerophosphate formulation were investigated. According to rheological study, gelation lag time of chitosan/β-glycerophosphate （GP） solutions varied from 2 to 60min with different deacetylation degree of chitosan, pH, gelation temperature, and the particles in the sol. The gelation properties were also found to influence the release profilles of a hydrophilic drug, 5-fluorouracil （5-FU）. Morphological examination by scanning electron microphotography demonstrated that large ＂pores＂ occurred during the gel-forming process, which created hydrophilic environment and led to the rapid initial release of the drug （85% in f＇LrSt 8h）. Poly-3-hydroxybutyrate （PHB）, a biodegradable material, was applied here as scaffold to capture 5-FU into microparticles with high encapsulation efficiency by solvent-nonsolvent method. Combination of these microparticles into the chitosan-β-GP formulation could drop the rapid initial release from 85% down to 29% in the optimized PHB content （75%, by mass）. The release could sustain for about 10 months. Tiffs study provided an understanding of the potential of injectable implant using thermosensitive chitosan-β-GP formulation containing PHB based particles for the water soluble drugs that need the property of long-term delivery.
