Objective      To determine the effects of self-microemulsifying drug delivery system (SMEDDS) on the relative bioavailability of artemether (ARM) in rats after oral administration

and to set up an HPLC-MS/MS method to determine the concentration of ARM in rat plasma.       Methods      Twelve rats were randomly divided into two groups

which were separately treated with a single dose of 120 mg/kg ARM suspension and 20 mg/kg ARM SMEDDS. The concentration of ARM in rat plasma was tested

and t

he pharmacokinetic parameters and the relative bioavailability of ARM SMEDDS were calculated.       Results      The linear range of ARM in rat plasma was 5.035 to 402.8 ng/mL (r=0.999 7). The intra-day and inter-day RSDs were less than 15%. After a single dose of 120 mg/kg ARM suspension or 20 mg/kg ARM SMEDDS

pharmacokinetic parameters were: C

max

96.33±37.34 and 183.59±48.32 ng/mL

respectively

AUC

0→t

304.86±75.27 and 842.18±151.55 ng·h/mL

respectively

and AUC

0→∞

322.66±79.32 and 979.90±172.71 ng·h/mL

respectively. The relative bioavailability of ARM SMEDDS was 1 658% and 1 822% calculated with AUC

0→t

and AUC

0→∞

respectively.       Conclusion      SMEDDS significantly improves the oral bioavailability of ARM and may be a promising carrier for ARM.