MEASUREMENT AND CORRELATION OF SOLUBILITIES OF SALICYLIC ACID IN WATER AND COSOLVENT SYSTEMS USING HPLC

摘要

Development of the drug with high medical activity is important in the pharmaceutical research. However, the solubilities in water of such drugs are quite low. Therefore, the enhancement of the solubility in the presence of the cosolvent is useful, and the selection of the cosolvent is important. This study aims to the detailed measurement of the solubilities for poor water solubility drugs and the consideration of the enhancement of the solublities by adding the cosolvent. In this study, solubilities of salicylic acid in five pure components: water, acetnitrile, methanol, ethanol, and ethyl acetate, and four mixtures containing cosolvent: methanol + water, ethanol + water, ethanol + ethyl acetate, poly ethylene glycol (PEG) 300 + water, ware determined using High-Performance Liquid Chromatography (HPLC). The experimental solubility data were correlated by the modified Wilson and the combined NIBS/Redlich-Kister models.