Abstract: AIM: To establish an LC-MS MS method for determination of evodiamine concentration in rat plasma and to study its pharmacokinetic profile in rats. METHODS: Six rats were administrated (i.g.)evodiamine at the dose of 100 mg/kg.Blood samples were collected from eye socket.Evodiamine concentration in rat plasma was determined by LC-MS MS method.The pharmacokinetic parameters were calculated using DAS program. RESULTS: A good linear relationship was obtained in the concentration range (0.2-50.0 ng mL) studied (r2 =0.9997).Average recoveries ranged from 96.12 % to 99.46 %.Intra-and inter-day relative standard deviations were 4.61 %-13.51 % and 5.65 %-11.49 %, respectively.The main pharmacokinetic parameters of evodiamine were as follows:C_max(5.3±1.5) ng mL;t_max(22±8)min;t 1 2(451±176)min. CONCLUSION: A selective and sensitive liquid chromatography-tandem mass spectrometric (LC-MS MS)method for the quantification of evodiamine in rat plasma is developed and validated.This method is successfully applied for the pharmacokinetic studies of evodiamine in rats.

Key words: evodiamine, blood drug/Level plasma, LC-MS MS, pharmacokinetic studies