TY - JOUR T1 - Stereoselective inversion of (R)-(-)-benoxaprofen to the (S)-(+)-enantiomer in humans. JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 356 LP - 359 VL - 7 IS - 6 AU - R J Bopp AU - J F Nash AU - A S Ridolfo AU - E R Shepard Y1 - 1979/11/01 UR - http://dmd.aspetjournals.org/content/7/6/356.abstract N2 - The enantiomeric composition of benoxaprofen [(RS)-2-(P-chlorophenyl)-alpha-methyl-5-benzoxazoleacetic acid] in plasma and urine was determined after oral administration of both the racemic mixture and the (R)-(-)-enantiomer to normal human volunteers. Resolution of the diastereomeric amides, formed by the reaction of the enantiomers with (S)-(-)-apha-methylbenzylamine, was accomplished by gas chromatography. The (R)-(-1)-enantiomer of the parent drug was stereoselectively inverted to its (S)-(+) isomer in humans. ER -