QUANTITATIVE-DETERMINATION OF HEPARINOID MIMETICS IN HUMAN AND RAT PLASMA BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY

The investigated new class of heparinoid mimetics are spaced persulfat ed carbohydrates designed to increase the success rate of angioplasty and bypass surgery by preventing restenosis without increasing the ris k of bleeding. Due to the presence of sulfate groups, these compounds are highly charged and, for preclinical kinetic investigations only sm all sample volumes of rat plasma were available. Therefore, capillary electrophoresis (CE) was applied. A bioanalytical method based on mice llar elektrokinetic chromatography (MEKC) with UV-detection was develo ped for the selective quantitation of heparinoid mimetics (e.g., Ro 48 -0843, Ro 48-3151, Ro 47-6199 and Ro 48-8722) in plasma. Using this me thod, only small volumes of plasma were required, which could be intro duced directly into the separation capillary after 1:1 dilution with 1 00 mM aqueous sodium dodecyl sulfate (SDS). For increased sample throu ghput, an additional ultrafiltration step was performed after SDS-dilu tion of the plasma sample, improving both reproducibility and robustne ss of the method considerably. The sensitivity of the new method (3 mu g/ml) was sufficient to follow plasma levels in pharmacokinetic studi es. The practicability of this easy and rapid assay was demonstrated b y the analysis of more than 350 plasma samples from pharmacokinetic st udies performed in rats.