Determination and evaluation of solubility parameter of satranidazole using dioxane-water system

Satranidazole, a potent broad spectrum antiprotozoal, is a poorly water-soluble drug and has low bioavailability on oral administration. One of the important methods to improve the solubility and bioavailability of a less water-soluble drug is by the use of cosolvents. The solubility enhancement produced by binary blends with a cosolvent (dioxane) was studied against the solubility parameter of solvent blends (d1 ) to evaluate the solubility parameter of drug (d2 ). Solubility parameter of drug (d2 ) was evaluated in blends of dioxane-water system. The results obtained were compared with the d2 values obtained using Molar Volume Method and Fedor′s Group Substitution Method. The binary blend water-dioxane (10:90) gave maximum solubility with an experimental d2 value of 11.34 (Cal/cm 3 ) 0.5 that was comparable to the theoretical values of 11.34 (Cal/cm 3 ) 0.5 determined by Molar Volume Method and 11.3928 (Cal/cm 3 ) 0.5 when determined by Fedor′s Group Substitution Method, which is in good agreement with solubility measurement method.