Preparation and characterization of 5-Fluorouracil loaded chitosan microspheres by a two-step solidification method

Chitosan, as a natural biopolymer, has potential applications in controlling the release of drugs due to its unique natural and physiochemical properties. Conventionally, an emulsion crosslinking method was used to prepare chitosan microspheres. In this study, a novel method of preparing 5-fluorouracil-loaded chitosan microspheres was established by combining the emulsification technique and a two-step solidification method using both glutaraldehyde (GTA) and tripolyphosphate (TPP) as crosslinking agents. The microspheres were characterized by surface morphology, encapsulation efficiency, yield of microspheres and drug release profile in vitro. The optimal chitosan microspheres were achieved by crosslinking chitosan with both TPP (0.1%, pH 4.0) and GTA (1.0%, v/v) with span-80 additive under a crosslinking time of 1 h with TPP and GTA, respectively.