title: Quantitative analytical methods for the determination of a new hypertension drug, CGS 25462, and its metabolites (CGS 25659 and CGS 24592) in human plasma by high-performance liquid chromatography.
abstract: Two simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) methods were developed and validated for the quantitative determination of a novel hypertension drug CGS 25462 and its major metabolites CGS 24592 and CGS 25659 in human plasma. CGS 25462 and CGS 25798 (internal standard) were purified by one-step liquid-liquid extraction with methylene chloride. The metabolites were analyzed on HPLC after plasma protein precipitation with 10% trichloroacetic acid (TCA). Separations were achieved on a Zorbax RX C18 column. All compounds were detected by using a fluorescence detector. The excitation wavelength was 254 nm, and emission was monitored at 325+/-12.5 nm. Assessment of recovery and reproducibility indicated good accuracy and precision. Over the validation concentration range of 10 to 1000 ng/ml for CGS 25462 and 25 to 5000 ng/ml for both metabolites, overall mean relative recoveries were 96% for CGS 25462, 101% for CGS 25659 and 107% for CGS 24592, and the coefficients of variation were 4.6 to 13% for CGS 25462, 9.5 to 13% for CGS 25659 and 7.7 to 15% for CGS 24592. The limits of quantification (LOQs) were 10 ng/ml for CGS 25462 and 25 ng/ml for CGS 24592 and CGS 25659, which were of sufficient sensitivity to measure the concentrations of CGS 25462, CGS 25659 and CGS 24592 in plasma samples from normal volunteers following a single 800 mg oral dose.
authors.affiliation: Bioanalytics and Pharmacokinetics, Research Department, Novartis Corporation, Summit, NJ 07901, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Maniara
authors.forename: A
authors.initials: A
authors.lastname: Cipriano
authors.forename: M L
authors.initials: ML
authors.lastname: Powell
mesh_terms: D000284:Administration, Oral; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002940:Circadian Rhythm; D006207:Half-Life; D006801:Humans; D008297:Male; D063065:Organophosphonates / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry; D011355:Prodrugs / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D011480:Protease Inhibitors / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; C086164:CGS 24592; C112151:CGS 25659; D063065:Organophosphonates; D011355:Prodrugs; D011480:Protease Inhibitors; C086165:CGS 25462; D010649:Phenylalanine