Size and morphology controlling of PLGA microparticles produced by electro hydrodynamic atomization

Among the various methods used to produce microparticles, electrospraying is becoming increasingly popular, and it has the advantage of control over the size, shape and morphology of the produced particles. Particle size and morphology are the main factors used to control the rate of microsphere degradation and drug diffusion. The aim of this study was to use some process and solution parameters of the electrospraying such as flow rate, collecting distance, nozzle diameter and polymer molecular weight to control size, shape and morphology of the produced particles. Tests demonstrated that the size of microparticle can be fine-tuned by adjusting the variables of flow rate, collecting distance and nozzle diameter. Other relevant factors that can be as tuning parameters were those of solvent vapor pressure and application of a polymer mix with different molecular weights. Results showed that microparticle size increased under an increased flow rate and needle gauge setting and a decreased electrical field. Results of the tests showed that morphology of the produced microsphere could be adjusted by the aforementioned parameters. For example, by lowering solvent vapor pressure by adding solvent with a high boiling point, the morphology was changed from a textured surface to a smooth one. Molecular weight of the polymer had a significant effect on morphology, whereas polymer with a low molecular weight caused defect in the produced microparticle, and a high molecular weight produced cup-like morphology, but a polymer mix that constituted polymers of high and low Molecular weights improved morphology of the produced particles. Copyright (c) 2015 John Wiley & Sons, Ltd.