Rapid, simultaneous determination of lopinavir and ritonavir in human plasma by stacking protein precipitations and salting-out assisted liquid/liquid extraction, and ultrafast LC-MS/MS.

Lopinavir and ritonavir are co-formulated in Kaletra approved for the treatment of human immunodeficiency virus infection. A validated analytical method is mandatory for clinical development and therapeutic drug monitoring. Here we are reporting a method for rapid, simultaneous determination of lopinavir and ritonavir in human plasma with stacked protein precipitations and salting-out assisted extraction (SALLE), and ultrafast LC-MS/MS detection.

High-throughput salting-out assisted liquid/liquid extraction and ultrafast LC for same-day delivery of first-in-human bioanalytical data.

Background: With the need of fast-paced drug development, rapid delivery of bioanalytical data becomes a trend. Here, we present a strategy to demonstrate same-day data delivery.

Results: A novel salting-out assisted liquid/liquid extraction (SALLE) with acetonitrile and a MS-friendly salt was used to extract analyte from the first-in-human study plasma samples and the extract was successfully injected into ultrafast chromatography.