Objective:To develop an HPLC-FLU method for the determination of capsaicin in rabbit plasma and to study its pharmacokinetics.Method: Six rabbits were given capsaicin nanoemulsions and ethanol solution（1mg.kg-1） via ear vein by double cycle crossover design

and after 3

6

9

12

15

25

40

60 and 120 min

blood samples were collected.HPLC-FLU was established to determine the plasma concentration of capsaicin and the pharmacokinetic evaluation was carried out.Result:The linear range of capsaicin was 0.197-49.3 mg.L-1（r = 0.999 6） and the limit of detection of capsaicin was 5.9 ng.mL-1

the average recovery was 102.5% ～ 107.6% with RSD < 5%.The t1/2 of capsaicin nanoemulsions and solution was（11.77 ± 2.32） min and（9.53 ± 2.19） min respectively

and the AUC was（5 311 ± 1 324.6） ng.mL-1.kg-1.min and（4 909.5 ± 1 110.4） ng.mL-1.kg-1.min respectively.Conclusion:This assay method is simple

precise and sensitive enough for the pharmacokinetic study of capsaicin.The pharmacokinectics parameters between capsaicin nanoemulsions and solution had no significant difference（t test

P > 0.05）.