Iranian Association of Pharmaceutical ScientistsIranian Journal of Pharmaceutical Sciences1735-24447120110101Prediction of Satranidazole Solubility in Water-Polyethylene Glycol 400 Mixtures Using Extended
Hildebrand Solubility Approach17242146ENPavan B.RathiDepartment of Pharmaceutics, Shri Bhagwan College of Pharmacy, N-6, CIDCO,
Auranagabad-431003, IndiaJournal Article20100910 The Extended Hildebrand Solubility Parameter Approach (EHSA) is used to estimate the solubility of satranidazole in binary solvent systems. The solubility of satranidazole in various water-PEG 400 mixtures was analyzed in terms of solute-solvent interactions using a modified version of Hildebrand-Scatchard treatment for regular solutions. The solubility equation employs term interaction energy (W) to replace the geometric mean (δ<sub>1</sub>δ<sub>2</sub>), where δ<sub>1</sub> and δ<sub>2</sub> are the cohesive energy densities for the solvent and solute, respectively. The new equation provides an accurate prediction of solubility once the interaction energy ‘W’ is obtained. In this case, the energy term is regressed against a polynomial in δ<sub>1</sub> of the binary mixture. A quartic expression of ‘W’ in terms of solvent solubility parameter was found for predicting the solubility of satranidazole in water-PEG 400 mixtures. The expression yields an error in mole fraction solubility of ~2.17%, a value approximating that of the experimentally determined solubility. The method has potential usefulness in pre-formulation and formulation studies during which solubility prediction is important for drug design.http://www.ijps.ir/article_2146_02b3fb31919419aee173692181ba4639.pdf