ABSTRACT
Objective:To evaluate the in vitro release behavior of doxorubicin(Dox)-loaded microspheres and the stability of Dox during encapsulation process and in vitro release.Methods: Dox-loaded microspheres were prepared by double emulsion(W/O/W) method with poly(lactic-co-glycolic acid)(PLGA) as the carrier material.The physical and chemical characteristics of microspheres,including the mean diameter,morphology,drug entrapment efficiency and loading rate,were evaluated.The in vitro release behavior and its influencing factors were determined by ultraviolet spectrophotometry.Dox stability was evaluated by HPLC method during the encapsulation process and in vitro release.Results: The prepared microspheres had a complete spheric shape and dispersive quality.The mean diameter of the microspheres was 85 ?m;the drug entrapment efficiency was 95.1%;and the loading rate was 14.8%.Releasing rate of the microspheres slowed down with the increase of PLGA concentration and the decrease of W/O value.The encapsulation process had no obvious effect on the stability of Dox,while Dox degraded during in vitro release as the prolongation of time.On day 10,the peak area of degraded material accounted for 2.46%.Conclusion: Dox can be encapsulated in the microspheres by double emulsion method and different release rates of Dox can be achieved by adjusting PLGA concentration and W/O volume ratio.