OBJECTIVETo investigate the effect of ceftiofur hydrochloride on the pharmacokinetics of matrine in rats.

METHODThe rats were divided into two groups: one group was administrated with matrine only (control group) and the other was administrated with matrine in combination with ceftiofur hydrochloride. HPLC-UV method was used for determining the plasma concentration of matrine in both groups. The pharmacokinetic parameters were calculated from the plasma concentration-time data using the DAS 2. 1. 1 software program.

RESULTThe main pharmacokinetic parameters for the control group were C(max) = 21.113 9 mg x L(-1), T(max) = 0.75 h, t1/2alpha = 1.34 h, t1/2beta = 3.509 h, AUC(0-t) = 90.984 mg x h(-1) x L(-1) and AUC(0-inifinity) = 100.346 mg x h(-1) x L(-1), and the data for the combination group were C(max) = 11.707 mg x L(-1), T(max) = 0.917 h, t1/2alpha = 1.598 h, t1/2beta = 3.247 h, AUC(0-t) = 53.28 mg x h(-1) x L(-1) and AUC(0-inifinity) = 60.035 mg x h(-1) x L(-1).

CONCLUSIONThe plasma concentration of matrine and bioavailability in combination group were significantly lower than those of the control group. In combination group, matrine had a higher clearance and volume of distribution in the central compartments, as well as a lower volume of distribution in the peripheral compartments.