ABSTRACT
Objective:To determine the equilibrium solubility and n-octanol/water partition coefficients (Papp)of cinnamon acid and cinnamaldehyde. Methods:The equilibrium solubility of cinnamon acid and cinnamaldehyde in different solutions was determined by HPLC,and their n-octanol/water partition coefficients were determined by a shaking flask method combined with HPLC-DAD. Results:When the pH of solution was 7.8,the equilibrium solubility of cinnamon acid was the largest,while that of cinnamaldehyde was the largest in pH 6.8 solution. The scopes of lgPappof cinnamon acid and cinnamaldehyde in different buffer solutions(pH 1.2-7.8) were -1.04-2.27 and 0.29-1.67, respectively, while those in n-octanol/water solvent were 0.85 and 1.26, respectively. Conclusion:The method is simple,accurate and fast to predicate the absorption of chemical components. In gastrointestinal physiological environment,cinnamaldehyde has good absorption, while cinnamon acid is with poor absorption in stomach and with better absorption in intestinal.