Solubility Prediction of Satranidazole in Methanol-Water Mixtures Using Extended Hildebrand Solubility Parameter Approach

Models for predicting solubility of drugs in solvent mixtures have an important practical application in drug formulation. Solvent mixtures are widely used in pharmacy, and theoretical and semiempirical approaches save experiments that are often expensive and time-consuming. The study of solubility behaviour of satranidazole in solvent blends and individual solvents ranging from non-polar to highly polar is essential. The total solubility parameter explains the interactions of the drug between solute and solvent. The solutions containing excess drug were shaken in a water bath for 72 h at 25^oC. The solutions attained equilibrium were then filtered and analyzed for drug content. The Extended Hildebrand Solubility Approach was used to process the solubility data of satranidazole. For understanding the solute-solvent interactions, total solubility parameter concept was utilized. A multiple regression method using the Extended Hildebrand Solubility Parameter Approach was applied to verify the solubility’s of satranidazole in pure polar solvents. Fedors group contribution method was used to calculate the solubility parameter of satranidazole and to support the results obtained from Extended Hildebrand Theory. The method has potential usefulness in preformulation and formulation studies during which solubility prediction is important for drug design.