Crystallization of acetaminophen in nano/micro scale using swirl mixing micro device under pressurized carbon dioxide

The fabrication of acetaminophen particles via supercritical antisolvent process with CO₂ as an antisolvent was studied. The experiments were conducted at temperatures of 35-50 °C and pressures of 8-15 MPa with 5-15 ml/min CO₂ flow rates. As a starting material, acetaminophen powder was dissolved in dimethyl formamide (DMF). Results of UV-vis spectrophotometry and GC-MS (gas chromatography mass spectrometry) analysis showed that there was no remaining DMF solvent in the acetaminophen particles products. It indicated that CO₂ has successfully removed DMF from acetaminophen particles products. The surface characterization by using fourier transform infrared spectroscopy (FT-IR) showed that the CO₂ solvent did not impregnate to the acetaminophen particles products. Results from scanning electron microscope (SEM) images showed that the acetaminophen particles products were successfully prepared in non-spherical shape morphologies with size less than 1 μm. Based on the result; this process seems a powerful method to modify the acetaminophen powder physically such as particle size reduction.