ABSTRACT
OBJECTIVE:To study relative bioavailability of dauricine self-microemulsifying drug delivery system (SMEDDS) in rats. METHODS:12 rats were randomly divided into dauricine SMEDDS group (20 mg/kg) and dauricine solution group (50 mg/kg),6 rats in each group. They were given relevant medicine intragastrically. Then,0.3 ml plasma was collected from orbital venous plexus before medication and 0.167,0.333,0.5,0.75,1,2,4,8,12,24,36 h after medication. The plasma concentration of da- uricine was determined by HPLC-MS/MS,and DAS 3.0 was used to calculate pharmacokinetic parameters and evaluate the relative bioavailability of dauricine with dauricine SMEDDS. RESULTS:The linear range of dauricine in plasma were 2.12-424 ng/ml (r=0.999 9);RSDs of intra-day and inter-day were all lower than 10%. Pharmacokinetic parameters of dauricine solution and dau-ricine SMEDDS were that cmax were(126.3±37.4)ng/ml and(179.6±51.5)ng/ml;t1/2 were(11.48±4.58)and(21.79±6.59)h;AUC0-t were (1 963.5±638.3)ng·h/ml and(2 535.8±739.5)ng·h/ml;AUC0-∞ were(2 256.3±703.5)ng·h/ml and(2 854.6± 768.7)ng·h/ml,respectively. The relative bioavailability of dauricine SMEDDS were 323% and 316% by calculating with AUC0-t and AUC0-∞,respectively. CONCLUSIONS:Intragastric administration of dauricine SMEDDS can improve relative bioavailability of dauricine significantly.