Rapid chiral high-performance liquid chromatographic assay for salmeterol and alpha-hydroxysalmeterol - Application to in vitro metabolism studies

A rapid and sensitive chiral high-performance liquid chromatographic (HPLC) assay for the simultaneous determination of salmeterol and its principal h uman metabolite alpha-hydroxysalmeterol is described. The two pairs of enan tiomers were resolved on a chiral-cellobiohydrolase column and detected by electrochemical detection at +700 mV. Standard curves were linear over the concentration range 0.1 to 4.0 mu M for alpha-hydroxysalmeterol enantiomers and 2.5 to 40.0 mu M for salmeterol enantiomers. Intra- and inter-day coef ficients of variation were <10%. The method was applied to a study of human hepatic metabolism in vitro which showed that microsomal metabolism of sal meterol to a-hydroxysalmeterol is not stereoselective. (C) 1999 Elsevier Sc ience B.V. All rights reserved.