Based on the principle of microchannel emulsification

a simple device with a detachable T-shaped microchannel junction was fabricated to prepare poly(lactic-co-glycolic acid) (PLGA) microparticles where aqueous solution of polyvinyl alcohol (PVA) was used as the continuous phase and PLGA dissolved in dichloromethane solution as the disperse phase.The effects of some important parameters such as the amount of emulsifier used in the continuous phase

the PLGA concentration

the disperse phase flow rate and the continuous phase flow rate on the average diameter of PLGA microparticles and the coefficient of variation (CV value) were examined in detail.The experimental results indicated that a decrease of the disperse phase flow rate

an increase of the continuous phase flow rate and increasing the amount of emulsifier used in the continuous phase led to the decrease of the average diameter of PLGA microparticles.When the PLGA concentration was between 5 g/L and 20 g/L

the average diameter of PLGA microparticles kept nearly constant.The uniform spherical PLGA microparticles with smooth surface were successfully prepared and no pores in the interior.By adjusting operating conditions

the average diameters of particles obtained ranged from 30 m to 200 m

and CV value of all the microparticles prepared under different operating conditions was below 15% while the lowest CV value was about 3%.This improved method can use organic solvents as disperse phase and avoid the easily blocking in the traditional method

which can be applied in the preparation of micrometer drug/polymer complex spheres with monodispersity and has great potential to be used in control-released drug delivery systems.