A study of polycaprolactone particles prepared using ultrasonicator via two step solvent evaporation method

One synthetic polymer that had seen extensive usage in biomedical applications was PCL. Nonetheless, differing PCL microparticle sizes resulted in diverse application types. Therefore, the main objective of this study was to investigate the effect of various processing parameters on particle size and the characteristics of polycaprolactone (PCL) microparticles that could be used in various applications. The parameters used in this study were water-oil ratio (w/o), feeding rate, amplitude, and molecular weight of PCL. The preparation method used was the solvent evaporation method using ultrasonicator probe to produce a small particle size. In this study, an optical microscope was used to observe the size of PCL microparticles. It was found that the size of the microparticles showed an increase from 0.94 μm to 0.99 μm because it was followed by increasing amounts of the oil phase. For feeding rate, the size of the microparticles obtained increased from 0.84 μm to 1.11 μm for 3:7 ratio and from 0.90 μm to 1.07 μm for 7:3 ratio when using different feedings from 0.5ml/min to 4ml/min. However, when the amplitude of the ultrasonicator probe increased, the size of the microparticles formed decreased, for 7:3 ratio from 1.04 μm to 0.94 μm, for 5:5 ratio from 1.05 μm to 0.92 μm and for 7:3 ratio from 0.98 μm to 0.79 μm, due to the higher shear energy to produce emulsion microparticle solution during the emulsification process. Lastly, for the molecular weights of PCL, the size of the microparticles obtained increased because 80,000 kg/mol, i.e., the higher molecular weights, could produce a larger particle size. In conclusion, parameters played a major role during the preparation of PCL microparticles, facilitating various types of applications.