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

•Solubility of spironolactone was measured using a static technique coupled with a gravimetric method.•Solubility was measured in the ranges of 308–338 K and 160–400 bar, respectively.•Solubility of spironolactone was ranged between 6.25 × 10−5 and 5.01 × 10−3 based on mole fraction.•Solubility data were correlated using MST and K–J models and PR-EoS.•Better predictions obtained using semi-empirical correlations compared with PR-EoS.

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.

Graphical abstractThe correlated solubility data of spironolactone using different correlations, (a) self consistency tests using MST model and (b) K–J model.Figure optionsDownload full-size imageDownload as PowerPoint slide