Beck O, Boreus L O, Lafolie P, Jacobsson G
Department of Clinical Pharmacology, Karolinska Hospital, Stockholm, Sweden.
J Chromatogr. 1991 Sep 18;570(1):198-202. doi: 10.1016/0378-4347(91)80216-y.
A method for the chiral high-performance liquid chromatographic analysis of methadone in plasma has been developed. The method employed organic solvent extraction, enantiomeric separation on a Chiral AGP column, and ultraviolet absorption detection at 212 nm. The intra-day variation in the quantification of methadone enantiomers was less than 9% at the 100 ng/ml level, and the values obtained correlated well with those from a gas chromatographic-mass spectrometric method. Results from patients indicate inter- and intra-individual differences in the ratio between l- and d-methadone in plasma during therapy with racemic methadone. In one patient, a higher level of d-methadone in plasma was caused by both faster elimination and lower bioavailability of l-methadone.
