Quantification of tipranavir in human plasma by high-performance liquid chromatography with UV detection

A simple method for the quantification of tipranavir, a new non-peptidic protease-inhibitor, was developed. An internal standard, prazepam, was added to 100 μl of plasma before a liquid–liquid extraction by 3 ml of tert-butyl methyl ether. The extracts were evaporated to dryness and reconstituted with 100 μl of mobile phase before being injected in the chromatographic system. The separation was made on a C8 column using sodium acetate buffer (pH 5):methanol:acetonitrile (35:30:35, v/v/v) as mobile phase. The detection was performed at a wavelength of 260 nm. The method was linear and has been validated over a concentration range of 2–80 mg/l. The mean precision and accuracy of the method were respectively, 10.5 and −9.1%. The mean recovery was 70.8%.