Quantification Of Exenatide In Biological Matrix By LC-MS/MS And Its Application

Exenatide has been reported widely on the regulation of glucose levels in blood during the treatment of diabetes and obesity.Exenatide in biological samples was mostly determined using either immunoenzymometric assay or radioimmunoassay(IEMA/RIA)and the lower limit of quantitation(LLOQ)of these assays can reach into pg/mL level.However,all of these types of methods lack of high specificity.On the contrary,the LC-MS/MS method has the advantages of high selectivity in the analysis of polypeptide drugs.Few LC-MS/MS method for exenatide was reported previously,in which assay sensitivity could meet the low-dose design of most pharmacokinetic or pharmacodynamic studies.In this study,a highly specific UPLC-MS/MS method for exenatide combined with SPE in monkey plasma was developed and validated.The LLOQ of the current method was achieved as 10 pmol/L(~40 pg/mL).Although the sensitivity of this method is slightly lower than that of immunoassay,it can meet our current analytical requirement of exenatide.To the best of our knowledge,this is the most sensitive LC-MS/MS method ever reported for exenatide,and this method can become an alternative choice besides immunoassays.The method was validated in terms of selectivity,linearity,accuracy,precision,recovery,matrix effect,dilution integrity,carryover and stability.It has been demonstrated to be selective,sensitive,simple,rapid andhigh-throughput.Furthermore,the method has successfully been used to analyze exenatde in preclinical biological samples.This study also provides reference for the accurate analysis of other polypeptide drugs by LC /MS/MS.