ABSTRACT
Objective:To determine the equilibrium solubility and the apparent oil/water partition coefficient of nebivolol hydrochloride to provide experimental basis for the development of new preparations.Methods:The concentration of nebivolol hydrochloride was determined by an HPLC method,and a saturated solution method and a shake-flask method were respectively applied to determine the equilibrium solubility and the apparent oil/water partition coefficient of nebivolol hydrochloride in water,0.1 mol·L-1 HCl solution and phosphate buffer solution with different pH values(pH2.0,pH6.8,pH7.4 and pH8.0).Results:At (37±0.5)℃,the equilibrium solubility of nebivolol hydrochloride in water and in 0.1 mol·L-1 HCl solution was 722.53 μg·ml-1and 56.07μg·ml-1,respectively.The apparent oil/water partition coefficient (Log P) of nebivolol hydrochloride was 1.17 and 1.32,respectively.Within the pH range of 2.0-7.4,with the increase of pH value, the equilibrium solubility and the Log P decreased and increased,respectively,while pH value increased from 7.4 to 8.0,the equilibrium solubility of nebivolol hydrochloride increased and Log P decreased.Conclusion:The method is accurate and reliable.Nebivolol hydrochloride has poor water solubility,and the equilibrium solubility and the Log P are both influenced by pH values.