Preparation and release of CTX microspheres encapsulated in starch graft PLA

Microspheres containing drug were prepared by oil-in-water emulsification-solvent evaporation technique,with the self-made amphiphilic and biodegradable polymer,starch graft poly(lactic acid)(ST-g-PLA) as the carrier,and cefotaxime as the model drug.The effect of PVA,oil/water vacuum ratio(Vo/Vw),polymer concentration in organic solvent,and stirring speed on diameter of microsphere,drug loading and ecapsulation efficiency were discussed.The microspheres were characterized by IR,DSC and SEM.The degradation ability of the microspheres in four surroundings was examined,and the drug release in vitro was evaluated.The results showed that when concentration of PVA and ST-g-PLA were 2% and 30%,respectively,Vo/Vw was 1∶6,the prepared microspheres had spherical shape with uniformity size and good dispersion.The drug loading rate and encapsulation efficiency were 8.2% and 49.2%,respectively.The degradation rate of microspheres were: artificial intestinal liquidalkali liquidPBSacid liquid,and the sustained release was remarkable.