Studies on the intestinal absorption of crocin in rats and determination of the partition coefficient

AIM: To clarify both the character of the absorption and the stability of crocin in various sites along the intestinal tract, and also to determine the partition coefficient of crocin-1 in water/n-caprylic alcohol system. METHOD: The intestinal absorption and stability was investigated using in situ perfusion method in rats; Shaking flask test was used to determine the partition coefficient of crocin-1; Concentration of crocin-1 was detected by HPLC. RESULT: Decrease of Crocin-1 in various intestine segments is as follows: Duodenum 13.81%, Jejunum 9.89%, Ileum 10.07%, and Colon 10.04%, but crocin-1 can't be found in blood; Degradation of Crocin-1 during incubation in refluxing solution of various intestinal segments is as follows: Duodenum 13.01%, Jejunum 10.11%, Ileum 9.95%, and Colon 10.45%; The partition coefficient of crocin-1 P = 0.093 ± 0.004, logP = - 1.03 ± 0.02. CONCLUSION: The results suggest that crocin is unstable and can't be absorbed in the whole intestinal tract.