简介：AIM:TopreparepolylacticacidmicrospheresofErythromycinforLungtargeting.METHEDS:Theorthogonaltestdesignwasusedtooptimizethetechnology,ofpreparation.Thecharacterofthemicrospheres,drugreleaseinvitro,stabilityandtissuedistributionwereexaminedRESULTS:TheErythromycinpolylacticacidmicrosphereswasregularinitsmorphology.DrugwasenvelopedinmicrospheresbutnotphysicallymixedwithPDLLA.Theaverageparticlesizewas11.65μnwithover94%ofthemicrospheresbeingintherangeof5～20trn;Thedrugloadingandtheincorporationefciencywere18%and60%respectively.Themicrosphereswerestableforthreemonthat4℃androomtemperature.TheinvitroreleasepropertiescouldbeexpressedbytheHiguchi'sequation:y=28.067+3.8515t11/2(r=0.9834).Comparingwithinjection,thedruginmicrosphereswasmoreconcentratedinlungtissue.CONCLUSION:Erythromycinpolylacticacidmicrospheresshowedsignificantsustainedreleaseandlungtargeting.