Determination of eletriptan in plasma and saliva using automated sequential trace enrichment of dialysate and high-performance liquid chromatography

The use of the system, automated sequential trace enrichment of dialysates (ASTED), to prepare plasma and saliva prior to high pressure liquid chromat ography of eletriptan (HPLC) is described. Chromatographic identification o f one metabolite, UK-135,800 was also established. Using this technique the procedure was observed to be specific and linear over the range 0.50-250 n g/ml. The intra-batch imprecision (C.V.) of the method ranged from 0.56 to 5.70% at plasma eletriptan concentrations from 5.00 to 200 ng/ml, and the c orresponding inter-batch imprecision ranged from 1.44 to 6.36%. At these pl asma analyte concentrations, the overall inaccuracy (% bias) of the procedu re ranged from -5.00 to 1.50%. Similar performances were observed for the e stimation of eletriptan in saliva using near identical assay conditions. Th e application of the assay to a pharmacokinetic investigation during a clin ical study is presented. (C) 1999 Elsevier Science B.V. All rights reserved .