Ultrafine Paracetamol Particles formation by Using Supercritical Fluid

In this research, Ultrafine particles of paracetamol were produced by Rapid Expansion of Supercritical Solution (RESS). The experiments were conducted to investigate the effects of extraction temperature, extraction pressure, pre-expansion temperature, post-expansion temperature, spraying distance and nozzle diameter on particles size and morphology of paracetamol particles. The characterization of the particles was determined by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Liquid Chromatography/Mass Spectrometry (LC–MS) analysis. The average particle size of the original paracetamol was 20.8 µm, while the average particle size of paracetamol after micronization via the RESS process was between 0.259 µm and 1.089 µm depending upon the experimental conditions used. Moreover, the morphology of the processed particles changed to spherical and regular while the virgin particles of paracetamol were needle-shape and irregular. The results showed that the size of the precipitated paracetamol particles was smaller than that of original particles and RESS parameters can significantly affect the particle size.