Solubility of capecitabine and docetaxel in supercritical carbon dioxide: Data and the best correlation

The solubility values of some chemotherapeutic agents such as capecitabine (CPT), docetaxel (DTX), and 5-fluorouracil (5-FU) were evaluated in supercritical carbon dioxide (SC-CO2) at pressures in the range of 15.2–35.4 MPa and temperatures ranging from 308 to 348 K, using a simple static method. The solubility values observed ranged from y = 0.37 × 10−4 to 7.02 × 10−4 for DTX and y = 0.32 × 10−5 to 15.88 × 10−5 for CPT. The mole fraction solubility of 5-FU was less than 10−6 and was not detectable by the proposed solubility determination method. The solubility values measured for pure drugs were correlated using semiempirical density-based models (Chrastilʹs, VA, Yuʹs, Gordilloʹs, Jouybanʹs, Bartleʹs, MST, KJ, and Tanʹs models). The results showed that these models, with an overall average absolute relative deviation (AARD%) lower than 21%, could be applied for satisfactory solubility prediction at different pressures and temperatures. Among different models, the Tanʹs equation is more suitable to describe the solubility of CPT and DTX in SC-CO2.