Allopurinol is a relatively water-insoluble drug and, consequently, its efficacy was frequently limited by the dissolution or solubility phenomena. The purpose of this study to improve solid-state properties and behavior allopurinol via supercritical antisolvent (SAS) process using CO2 as an antisolvent. effects operating parameters: temperature (35–55 °C), pressure (80–100 bar), solution conce...