Recast Solubility Models for Correlating Solubility of Solid Drugs in Supercritical Carbon Dioxide

Solubilities of solid drugs in supercritical fluids were well represented by density models and mathematical models. In literature, several solubility models were reported, and some of them were observed to be redundant according to Gibbs phase rule. Therefore, the present work is aimed to address the redundant nature of the solubility models by recasting the existing solubility models with the help of the equation of state (EoS). Solubility models proposed by Adachi–Lu, Garlapati–Madras, Keshmiri et al., Si-Moussa et al., Belghait et al., Sodeifian et al. model 1, and Sodeifian et al. model 2 were considered for the study. Existing and recast versions of solubility models were evaluated with literature reported 20 drug compound's solubility data in supercritical carbon dioxide.