In this communication, micronized acetaminophen particles are investigated using the rapid expansion of the supercritical solution (RESS) process. According to the obtained results, the largest acetaminophen particle size was ≤ 40 nm with spherical and quasi-spherical morphology in comparison with unprocessed particles with needle shape and mean particle size of 80.32 µm. The effect of extraction pressure and temperature, pre-expansion temperature, and spaying distance on the acetaminophen particle size and morphology were studied. The results indicated that increases in the extraction pressure and temperature led to decreases acetaminophen particle size but increasing pre-expansion temperature and spaying distance had opposite effects. To investigate particle formation through the RESS process with more details, velocity, pressure, density, and temperature behavior of the supercritical solution and acetaminophen solubility in supercritical CO₂ was modeled. Ultimately, the population balance equation was solved based on the moment method and acetaminophen particle size distribution was predicted and the influence of coagulation phenomenon as a remarkable mechanism on particle size distribution was investigated.

在本次交流中，使用超临界溶液 (RESS) 过程的快速膨胀研究了微粉化对乙酰氨基酚颗粒。根据获得的结果，与针状和平均粒径为 80.32 µm 的未加工颗粒相比，对乙酰氨基酚的最大粒径≤ 40 nm，具有球形和准球形形态。研究了提取压力和温度、预膨胀温度和喷射距离对对乙酰氨基酚粒径和形貌的影响。结果表明，提取压力和温度的增加导致对乙酰氨基酚粒径减小，但增加预膨胀温度和喷射距离具有相反的效果。通过RESS过程研究粒子形成的更多细节，速度，压力，密度，₂被建模。最后，基于矩量法求解群体平衡方程，预测了对乙酰氨基酚的粒径分布，并研究了作为一种显着机制的混凝现象对粒径分布的影响。