Determination of the renin inhibitor Ro 42-5892 in human plasma by automated pre-column derivatization, reversed-phase high-performance liquid chromatographic separation and electrochemical detection after post-column irradiation.
The renin inhibitor Ro 42-5892 has been found to be very potent, thereby necessitating a sensitive assay method for the evaluation of its pharmacokinetics in man. We report here the development of a very sensitive and selective HPLC assay for the analysis of this compound in human plasma. Ro 42-5892 was extracted from plasma with dichloromethane, derivatized with 2,4-dinitrofluorobenzene and then chromatographed on a Novapak C18 column (150 x 3.9 mm I.D.) with acetic acid buffer (pH 7)-acetonitrile (100:85). Detection was performed by irradiation at 254 nm, followed by electrochemical oxidation at 550 mV. The extraction recovery of Ro 42-5892 from human plasma (mean 102%) was quantitative. With this method a limit of quantitation of 0.3 ng/ml was achieved. The assay was linear up to 5 ng/ml, had acceptable inter-assay precision (12.2%) and accuracy (9.3%) and was successfully tested for selectivity. This assay was successfully applied to over 250 samples from a pharmacokinetic study in hypertensive patients.
Leube
J
J
Pharma Division, F. Hoffmann-La Roche, Basel, Switzerland.
Fischer
G
G
D001322:Autoanalysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000706:statistics & numerical data; D004355:Drug Stability; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000097:blood* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D000092502:Renin Inhibitors
D007093:Imidazoles; D000092502:Renin Inhibitors; C065581:remikiren