Irbesartan (IRB) is used in the management of hypertension. IRB is a poorly water-soluble drug with very low aqueous solubility. This drug has poor bioavailability after oral administration. This study aimed at improving the dissolution of IRB through the preparation of solid dispersions (SDs) using supercritical fluid based on supercritical anti-solvent (SAS) technique. Solid dispersions of IRB were prepared by a surfactant named Pluronic(R) F-127 (briefly pluronic) at a ratio of 1:1. The physical mixtures were provided as controls. Drug solubility of samples was studied based on saturation solubility and the in vitro dissolution rate of the drug was investigated. The SAS formulation was characterized by UV-Vis, SEM, PXRD, DSC and FTIR. The dissolution rate and solubility of IRB improved remarkably with a non-ionic surfactant using SAS-based technique. SAS processes showed signs of less crystallinity of the drug due to the transformation of its crystalline state into the amorphous state. The analysis of dissolution data indicated that enhanced drug dissolution can be achieved where the SDs in the supercritical fluid process consisted of pluronic nanoparticles. Finally, the SAS-SD formulation showed an increase in relative bioavailability than the pure IRB. (C) 2016 Elsevier B.V. All rights reserved.