Determination of enantiomeric purity of the new D-2 dopamine agonist 2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0437) by reversed-phase high-performance liquid chromatography after pre-column derivatization with d(+)-glucuronic acid

This paper describes an enzymic derivatization procedure that allows accurate determination of very small amounts of enantiomeric impurities in the D-2 dopamine agonist 2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0437). After pre-column glucuronidation of the individual enantiomers, two diastereoisomers were formed which were separated by reversed-phase high-performance liquid chromatography. An enantiomeric purity of 99.84% was calculated for the (−)-enantiomer, against 99.89% for the (+)-enantiomer. The assay was validated by spiking 1% of the (−)-enantiomer in the (+)-enantiomer. A high accuracy (error 4.5%) and precision (coefficient of variation 2.9%, n = 5) of the method were establishe