Extended Hildebrand Solubility Approach applied to piroxicam in ethanol + 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 298.15K. 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.