The pharmacokinetics of dauricine in rats / 中国药理学通报

ABSTRACT

AIM To study the pharmacokinetic characters of dauricine(Dau) in rats after different administration ways. METHOD RP-HPLC method was used in the study. RESULT The results indicated that the plasma C-T curve conform to two-compartment open model after iv. The plasma concentration of Dau in rats after ig Dau 150 mg*kg-1 is low, less than 1 mg*L-1 of peak concentration. The absolute bioavailibility is about 16.6 %. The plasma concentration-time profile shows a double-peak phenomenon. The time taken to reach the peak is about 15 min after ig and the trough time is 3 h. The plasma concentration increased again in 4 h to form the second peak. The studies suppose a stomach-intestine recirculation of Dau is the major reason for double-peak phenomenon. Dau has a wide distribution in rat body. It lies in all tissues and organs in both adminastration ways. The tissue Dau concentration are hundreds times higher than that in plasma concurrently. Feces is the main route whereby Dau are excreted from the rats after ig 150 mg*kg-1. The excreted percentage through feces is 26.29 %, while through urine is 4.93%. The total amount is 31.22% after 48h of oral administration of Dau. The study of the mean percentage of the dose remaining in stomach, small intestine, large intestine and whole GI tract from each rat sacrificed at different times after oral administration of Dau suggest the stomach-intestine circle. CONCLUSION　The bioavailibility of Dau is low. The plasma drug concentration versus time curve shows an innormal double-peak phenomenon. Dau can distribute abroadly to almost all kinds of the tissues in rats. The main excretion routes are through feces and urine. The pilot study suggests that stomach-intestine circle be the main reason for the innormal double-peak phenomenon.