RESUMEN
A biodegradable modified guar gum microsphere was prepared for the first time by ionic gelation of the guar gum derivative containing quarternary ammonium group with tripolyphosphate at room temperature in the absence of emulsifying agent or organic solvent. Its average particle diameter was about 140 microm and the particle size had a narrow and normal gauss distribution. From the loading experiment of bovine serum album (BSA) with various concentrations, it was found that the encapsulation efficiency is more than 80%. By the investigation of in vitro release from the BSA-loaded microsphere, it was found that the BSA had a continuous release for more than 6 hours and the release percentage was affected by the initial concentration of the BSA and temperature.