Determination of Org NC 45 (a myoneural blocking agent) in human plasma using high-performance normal-phase liquid chromatography.

The assay for the quantification of Org NC 45 in human plasma is described in detail. It comprises ion-pair extraction and normal-phase liquid chromatography in conjunction with UV detection. An analogue, 17 beta-deacetyl-Org NC 45, is used as standard in the assay procedure. The accuracy and precision of the assay at 400 ng of Org NC 45 per ml of plasma are 0.7% and 2.8%, respectively. The detection limit is approx. 50 ng Org NC 45 per ml of plasma. The assay can be used for the pharmacokinetic evaluation of Org NC 45 in man.