Sensitive and Rapid Method for the Simultaneous Quantification of the HIV-Protease Inhibitors Indinavir, Nelfinavir, Ritonavir, and Saquinavir in Human Plasma by Reversed-Phase Liquid Chromatography

Abstract

A rapid, sensitive, and specific liquid chromatography method for the simultaneous determination of four protease inhibitors (indinavir, nelfinavir, ritonavir, and saquinavir) in human plasma is described. After a liquid-liquid extraction with terbutyl methyl ether and a sequential washing of the reconstituted sample with hexane, protease inhibitors are separated on a phenyl column using a simple binary mobile phase of ammonium acetate buffer:acetonitrile (48:52) (pH = 7.5) with an ultraviolet detection at 260 nm. The standard curves are linear in the range 0.025–1 μg/mL for saquinavir, 0.1–4 μg/mL for indinavir and nelfinavir, and 0.25–10 μg/mL for ritonavir, with an average recovery ranging from 79% to 99%, and with both low interday and intraday coefficients of variation (