Extended Hildebrand Solubility Approach applied to piroxicam in ethanol plus water mixtures

In this work the Extended Hildebrand Solubility Approach (EHSA) was applied to evaluate the solubility of the analgesic drug piroxicam in some ethanol + water mixtures at 298.15 K. Experimental solubility and some properties of fusion of this drug were used. An acceptable correlative capacity of EHSA was found using a regular polynomial model in order five (overall deviation 2.41%), when the W interaction parameter is related to the solubility parameter of the co-solvent mixtures. Nevertheless, the overall deviation obtained by using EHSA was the same as the one obtained directly by means of an empiric regression of the logarithmic experimental solubility as a function of the mixture solubility parameter. (C) 2013 Elsevier B.V. All rights reserved.