title: Determination of L-756 423, a novel HIV protease inhibitor, in human plasma and urine using high-performance liquid chromatography with fluorescence detection.
abstract: A method for the determination of L-756 423, a novel HIV protease inhibitor, in human plasma and urine is described. Plasma and urine samples were extracted using 3M Empore extraction disk cartridges in the C18 and MPC (mixed-phase cation-exchange) formats, respectively. The extract was analyzed using HPLC with fluorescence detection (ex 248 nm, em 300 nm), and included a column switching procedure to reduce run-time. The assay was linear in the concentration range 5 to 1000 ng/ml when 1-ml aliquots of plasma and urine were extracted. Recoveries of L-756 423 were greater than 84% over the calibration curve range using the described sample preparation procedures. Intra-day precision and accuracy for this assay was less than 9% RSD and within 7%, respectively. Inter-day variabilities for the plasma (n=17) and urine (n= 10) were less than 5% and 3% for low (15 ng/ml) and high (750 ng/ml) quality control samples. Bovine serum albumin (0.5%) was used as an additive to urine to prevent precipitation of L-756 423 during the storage of clinical samples. The assay was used in support of human clinical trials.
authors.affiliation: Merck Research Laboratories, Department of Drug Metabolism, West Point, PA 19486, USA. mark_rose@merck.com
authors.forename: M J
authors.initials: MJ
authors.lastname: Rose
authors.forename: S A
authors.initials: SA
authors.lastname: Merschman
authors.forename: E J
authors.initials: EJ
authors.lastname: Woolf
authors.forename: B K
authors.initials: BK
authors.lastname: Matuszewski
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D017320:HIV Protease Inhibitors / Q000032:analysis* / Q000097:blood / Q000652:urine; D015497:HIV-1 / Q000187:drug effects; D006801:Humans; D007189:Indans / Q000032:analysis* / Q000097:blood / Q000652:urine; D010879:Piperazines / Q000032:analysis* / Q000097:blood / Q000652:urine; D012015:Reference Standards; D015203:Reproducibility of Results; D012106:Research; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D017320:HIV Protease Inhibitors; D007189:Indans; D010879:Piperazines; C122089:L 756423