title: A simple and sensitive assay for determining plasma tipranavir concentration in the clinical setting by new HPLC method.
abstract: A simple method for the quantification of tipranavir, the first non-peptidic HIV protease inhibitor, was developed and validated. Quinoxaline, as internal standard, was added to 50 microl of plasma before a liquid-liquid extraction by 600 microl of protein precipitation solution. The extracts were diluted before being injected in the chromatographic system. Chromatographic separation was made on a C18 column using potassium phosphate buffer (pH 3.2) and acetonitrile with gradient. Detection was performed by an UV detector at 260 nm. Relative error at three control quality concentrations ranged from -1.81 to 1.72%. Intra-day (CV%) and inter-day (CV%) precision ranged from 0.94 to 2.55% and from 3.07 to 4.24%, respectively. LOQ and LOD were 0.090 microg/ml and 0.035 microg/ml, respectively. Mean recovery was 87.1%+/-2.4%. Calibration curve was linear up to 180 microg/ml. Concentration range when optimized (0.703-180 microg/ml) proved to be adequate to measure tipranavir concentration in HIV-1-positive patients, therefore this method could be suitable for therapeutic drug monitoring of this drug.
authors.affiliation: Department of Infectious Diseases, University of Turin, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149 Turin, Italy. antodav@inwind.it
authors.forename: Antonio
authors.initials: A
authors.lastname: D'Avolio
authors.forename: Mauro
authors.initials: M
authors.lastname: Sciandra
authors.forename: Marco
authors.initials: M
authors.lastname: Siccardi
authors.forename: Lorena
authors.initials: L
authors.lastname: Baietto
authors.forename: Daniel Gonzalez
authors.initials: DG
authors.lastname: de Requena
authors.forename: Stefano
authors.initials: S
authors.lastname: Bonora
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Perri
mesh_terms: D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy; D017320:HIV Protease Inhibitors / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D006801:Humans; D011725:Pyridines / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D011753:Pyrones / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013449:Sulfonamides
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D011725:Pyridines; D011753:Pyrones; D013449:Sulfonamides; C107201:tipranavir