Studies on Physicochemical Proprieties of Koumine and Stability of Koumine Solution

Objective To study the physicochemical proprieties of Koumine and the stability of Koumine solution. Methods High performance liquid chromatography(HPLC)are used to determine the equilibrium solubility and apparent oil/water partition coefficient of Koumine in different medium. The stability of Koumine solution was examined under the different pH and temperature. Results The equilibrium solubility of Koumine in water at 25℃ was 141mg/mL and decreased in basic medium. The apparent oil/water partition coefficient LgP was-1in neural and basic condition,whereas LgP was1in acidic condition. Between pH 3～9,the stability of Koumine solution was well sustained at 4 ℃and 25℃. However,the stability was significantly reduced under strong acidic condition(pH 3.0)at37℃. Conclusion Koumine is highly soluble in water. It is more lipophilic in basic condition than in acidic condition. Under strong acidic and high temperature condition,the stability of Koumine is poor.