Study On Metabolic Kinetic Characteristics And Metabolic Mass Balance Of Aspirin Eugenol Ester In Rats

Aspirin Eugenol Ester?AEE?is a new non-steroidal anti-inflammatory drug developed by Lanzhou Institute of Husbandry and Pharmaceutical Science of CAAS?LanZhou,China?.It can reduce aspirin's gastrointestinal irritation and enhance the stability of the volatile oil-eugenol.The pharmacy,pharmacodynamics and toxicology of AEE showed that AEE has a good druggability.As a new synthetic drug,the study on disposition behavior in vivo of AEE provides a basis for a comprehensive evaluation of the pharmaceutical properties of AEE and a reference for its rational clinical use.1.Four metabolites of eugenol were obtained by synthesizing method,such as eugenol sodium sulphonate;eugenol-?-D-glucuronic acid;3-?4-hydroxy-3-methoxyphenyl?-propylene-1,2-oxide;3-?4-hydroxy-3-methoxyphenyl?-propane-1,2-diol.Eugenol sulfate was synthesized through sulfonation of eugenol with chlorosulfonic acid using pyridine as the solvent and catalyst.Eugenol glucuronate were obtained in moderate to excellent yields via the reaction of eugenoland2,3,4-tri-O-acetyl-1-O-trichloroacetylimidoyl-?-D-glucopyranuronateusing catalytic BF₃·Et₂O in dichloromethane at-20?and then hydrolysis with sodium hydroxide in acetone-water solution.The reactions proved to be an efficient methodology for the synthesis of eugenol glucuronate and eugenol sulfate.The two phase I metabolites of eugenol were obtained by peroxidation of eugenol and further hydrolysis reaction.The object products have been verified by NMR and ESI-MS.The four metabolites of eugenol can be used as the reference substances in the metabolit quanity studies of AEE in vivo.2.The pharmacokinetic of AEE and its main active metabolites in rats were investigated.The quantitative analysis methods of AEE,aspirin,eugenol and salicylic in the rat plasma with LC-MS/MS were established and validated.Thirty-two Sprague-Dawley rats were selected and divided into 3 groups,administered with a dose of 20 mg/kg,50 mg/kg,and 125 mg/kg of AEE after jugular vein cannulation,respectively.The results showed that AEE and aspirin was almost undetectable in plasma.The concentration of eugenol was low in those time points with low and medium dose of AEE.The concentrations of salicylic acid can be well determined at all time points.The pharmacokinetic profiles of salicylic acid and eugenol were obtained.The concentration of salicylic acid and eugenol in plasma was confirmed to the one-compartment model.AUC and C_maxax of SA showed a good correlativity with the doses administered of AEE.But there were no significant differences in half-life and T_max of SA between different doses.The established determination method was effective,convenient and sensitive,which was suitable for pharmacokinetics study of AEE and its metabolites in rat plasma.This method also provided technical reference and theoretical basis for future research of AEE disposal in vivo and administrational duration.3.Mass balances of AEE in rats were investigated.Seven Sprague-Dawley rats were selected and given with a dose of 50 mg/kg AEE.The urine were collected at 0-6 h,6-12 h,12-24 h,24-36 h,36-48 h after administration.All samples were analyzed by LC-MS/MS and the concentrations of 13 major metabolites were determined and then analyzed for the ratio of each metabolite.The results showed that the average recovery of metabolites with aspirin as the mother structure in urine of SD rats after oral administration of AEE was 72.26%.The proportion of SA detected in the metabolites was the largest,reaching 42%.The total proportion of phase II metabolites SUA,SAG,and SAAG was approximately 51%,but The proportion of such phase?metabolite as GA was only 7%.The majority phase II metabolite was SUA,accounting for 36%.The proportions of SAG and SAAG were basically the same.The average recovery of metabolites with eugenol as the mother structure was 87.27%,and the main phase II metabolites were E-S and E-G.The proportions of E-S and E-G accounted for 55%and 41%of the total excretion.Based on relative references and lots of experiments,five I phase metabolites of eugenol were selected for the study.Finally,only two metabolites met the measurement requirements,and their contents were very little.