Determination of equilibrium solubility of zolmitriptan and its apparent oil/water partition coefficient / 重庆医科大学学报

ABSTRACT

Objective:To determine the equilibrium solubility of zolmitriptan in various media and its partition coefficients for the n-octanol-water/buffer solution systems.Methods:A high performance liquid chromatography was established and used to detect the concentration of zolmitriptan;the partition coefficients for the n-octanol-water/buffer solution systems of zolmitriptan were determined by shaking flask method.Results:The equilibrium solubility of zolmitriptan in water was 12.6 g/L at 37℃.The equilibrium solubility of zolmitriptan were 1 382.0,553.0,85.2,71.5,47.1,11.5 and 4.85 g/L in buffer solutions with pH values of 3.6,4.5,6.0,6.8,7.4,8.0 and 9.0 respectively.Papp of zolmitriptan was 0.013 in water and were 0.04,0.06,0.14,0.20,0.23,0.25 and 1.44 in buffer solutions with different pH values.Conclusion:In the range of pH3.6 to pH 9.0,the equilibrium solubility of zolmitriptan was decreased while the apparent oil/water partition coefficient was increased with the increasing of pH values.