OBJECTIVEDevelop an LC-MS method to determine evodiamine and rutaecarpine in rats plasma simultaneously. The method was employed to investigate pharmacokinetics of evodiamine and rutaecarpine.

METHODBlood samples were collected in different time after oral administrated with the extracts of Euodiae Fructus, the plasma concentration of evodiamine and rutaecarpine was determined by LC-MS, pharmacokinetic parameters were calculated by WinNonlin 5.1 software.

RESULTThe linear ranges of evodiamine and rutaecarpine were 0.5-100 microg x L(-1) (r = 0.995 9), 1-200 microg x L(-1) (r = 0.999 3) respectively. The average recovery were exceeded 76% (n = 5), the precision of inner-day and inter-day were less than 15%. The pharmacokinetics parameters AUC, t1/2, CL _F of evodiamine were: (2 215.24 +/- 414.49), (4 230.62 +/- 753.77), (13 219.21 +/- 3 740.95) min x ng(-1) x mL(-1); (146.57 +/- 38.38), (114.38 +/- 14.65), (163.37 +/- 8.83) min; (184 607.29 +/- 32 502.21), (192 878.22 +/- 31 897.37), (19 3224.63 +/- 62 278.74) mL x min(-1). The pharmacokinetics parameters AUC, t1/2, CL_F of rutaecarpine were (2 283.53 +/- 298.51), (4 424.84 +/- 276.95), (14 239.93 +/- 3648.27) min x ng(-1) x mL(-1); (167.10 +/- 15.82), (131.58 +/- 20.07), (144.41 +/- 13.65) min; (1 177 340.54 +/- 2 4942.21), (181 262.92 +/- 11 162.22), (177 508.10 +/- 52 611.80) mL x min(-1).

CONCLUSIONThe method described in this report has high sensitivity and selectivity, and was suitable for pharmacokinetic studies of evodiamine and rutaecarpine. The kinetic process of evodiamine and rutaecarpine in rats in vivo were all yielded to be one-compartment model.