The electrospray technique was used to prepare poly［(ethylglycino)(phenylalanine ethyl ester) phosphazene］ microparticles with very low polydispersity.By replacing the chloroform atoms of polydichloro\|phosphazene with alanine ethyl ester and glycine ethyl ester subsequently

poly［(ethylglycino)0.30(phenylalanine ethyl ester)0.70phosphazene］ (PGPP) was obtained and electrosprayed.The effects of processing parameters such as solvent

polymer concentration

liquid flow rate

applied voltage and receiving distance on the morphology and size of PGPP particles were investigated systematically.The morphologies of the electrosprayed PGPP microparticles were observed by scanning electron microscope (SEM)

and the particle sizes were analyzed by using a software ImageJ basing on SEM photos.It was found that the morphology of PGPP microparitcles depended on polymeric concentration significantly.As PGPP concentration increased from 0.10 g/mL to 0.30 g/mL

rounder particles could be formed.The particles electrosprayed from PGPP solutions in tetrahydrofuran (THF) were less agglomerated than those obtained from the 1

4-dioxane solution

which was thought as a consequence of the faster de-solvent rate of THF.On the other hand

the parameters including the liquid flow rate

applied voltage and receiving distance mainly influenced the size of microparticle

among which

the effect of liquid flow rate on the particle size was most remarkably.The particle size increased with the increasing flow rate

generally obeying the Scaling law

while it decreased by increasing voltage or distance.Experimental data demonstrated that PGPP microparicles with nearly spherical morphology and a size of 1～2 m could be produced by electrospraying 0.25 g/mL PGPP/THF solution at the optimized parameters.In result

PGPP microparicles with controllable morphology and size could be obtained by changing the various processing parameters of electrospray

and this technique could be used to fabricate drugloaded polyphosphazene microparticles for further study on the drug controlled release behaviors

which might have potential applications in inhaled drug delivery systems.