Solubility of spironolactone in supercritical carbon dioxide: Experimental and modeling approaches

In the present work, the solubility of spironolactone in supercritical carbon dioxide was measured using a static technique coupled with a gravimetric method. The solubility of this model drug was measured in the ranges of 308–338 K and 160–400 bar, respectively. The results showed that the solubility of spironolactone was in the range of 6.25 × 10−5–5.01 × 10−3 based on the mole fraction at the studied temperatures and pressures. In addition, the measured solubility data were correlated using semi-empirical density based correlations (Mendez Santiago–Teja (MST) and Kumar and Johnston (K–J)) and an equation of state (Peng–Robinson (PR)). Obtained results showed better capability of the semi-empirical correlations compared with the PR-EoS for correlating the solubility of spironolactone at the studied temperatures and pressures.