Solubility of 1,3-Dimethyl-7H-purine-2,6-dione (Theophylline) in Supercritical Carbon Dioxide

Abstract

This contribution provides complementary experimental data of solubility (y2, molar fraction) of solid 1,3-dimethyl-7H-purine-2,6-dione (theophylline) in supercritical CO2 as a function of temperature (313 K ≤ T ≤ 333 K) and pressure (10 MPa ≤ P ≤ 44 MPa). A static-analytic methodology was used with standard deviations from average solubility measurements of ≤ 38 % and with estimated inherit errors ≤ 25 %. The solubility of theophylline increased with the CO2 density from 0.33·10−5 mol·mol−1 at 797.2 kg·m−3 (313 K, 16 MPa) to 3.3·10−5 mol·mol−1 at 890.2 kg·m−3 (333 K, 40 MPa). The solubility increased with pressure and temperature. Experimental solubilities were correlated with a density-based model with three adjustable parameters, which was valid for solvent densities in the range of (400 to 950) kg·m−3.