Katsumi Tochigi1, Hiroyuki Matsuda1, Kenta Kaburagi1, Kiyofumi Kurihara1, and Kazuo Tomono2. (1) Department of Materials and Applied Chemistry, Nihon University, 1-8 Surugadai, Kanda, Chiyoda-ku, Tokyo, 101-8308, Japan, (2) College of Pharmacy, Nihon University, Chiba, Japan
To find the medicine with high medical-activity is important in the pharmaceutical research. But the solubility in water of such drugs is quite few. So the selection of co-solvent is useful from the practical point of view. This study aims to the measurement of solubilities for poor solubility pharmaceutical substance and to the check of the enhancement of the solubilities by adding cosolvents. Solubilities of salicylic acid in water, methanol + water, ethanol + water, 1,4-dioxane + water, and polyethyleneglycol(PEG)300 + water, were determined at 298.15K using High-Performance Liquid Chlomatography (HPLC). The experimental solubility data were correlated by the log-linear model.