High-performance liquid chromatography assay for the determination of the HIV-protease inhibitor tipranavir in human plasma in combination with nine other antiretroviral medications

An accurate, sensitive and simple reverse-phase (RP) high-performance liquid chromatography (HPLC) assay has been developed and validated for the simultaneous quantitative determination of tipranavir with nine other antiretroviral drugs in plasma. A liquid–liquid extraction of the drugs in tert-butylmethylether (TBME) from 200 μL of plasma is followed by a reversed phase gradient HPLC assay with UV detection at 210 nm. The standard curve for the drug was linear in the range of 80–80,000 ng/mL for tipranavir; 10–10,000 ng/mL for nevirapine, indinavir, efavirenz, and saquinavir; and 25–10,000 ng/mL for amprenavir, atazanavir, ritonavir, lopinavir, and nelfinavir. The regression coefficient (r2) was greater than 0.998 for all analytes. This method has been fully validated and shown to be specific, accurate and precise. Due to an excellent extraction procedure giving good recovery and a clean baseline, this method is simple, rapid, accurate and provides excellent resolution and peak shape for all analytes. Thus this method is very suitable for therapeutic drug monitoring.