Quantitative estimation of gemcitabine by HPLC in plasma

A method for estimating the antitumor agent gemcitabine in plasma by isocratic HPLC was developed. Sample preparation consisted of precipitating proteins with a mixture of acetonitrile and methanol (9:1) with subsequent acidification of the extract with glacial acetic acid. Supernatants were then evaporated to dryness in a rotary vacuum evaporator at 42°C. The dry residue was dissolved in the mobile phase, which consisted of a mixture of acetate buffer pH 5.0 and acetonitrile (97.5:2.5). UV detection of gemcitabine was performed at 282 nm. The detection limit for this compound was 1 µg/ml. This method can be used to study the pharmacokinetic characteristics of the agent within the frameworks of the protocol “Studies of dose-dependent regimes of long-term infusions of gemcitabine in patients with local and disseminated pancreas cancer.”