Objective:To investigate the impact of preparation technique on in vitro release properties of tolterodine-loaded microspheres.Methods:Tolterodine poly(lactic-co-glycolic acid)(PLGA) microspheres were prepared with O/W emulsion solvent evaporation method and characterized by SEM,DSC and FT-IR.The particle size,encapsulation efficiency,and in vitro release rate of tolterodine from the microspheres were studied.Results:The microspheres were spherical in shape with a smooth surface.The effects of the molecular...