Sensitive and rapid method for the quantitation of amoxicillin in minipig plasma and milk by LC-MS/MS: A contribution from the IMI ConcePTION project.

The IMI project ConcePTION was launched to fill the knowledge gap of using medicines during pregnancy and lactation. To achieve this goal, several studies are being conducted, including the bioanalysis of amoxicillin in minipig plasma and milk. A high-throughput, robust and reliable liquid chromatography tandem mass spectrometry method was developed and validated according to FDA and EMA guidelines to determine the concentrations of amoxicillin in a large number of minipig plasma and milk samples. Chromatographic separation was achieved on a Luna® Omega Polar C18, 1.6 μm, 100 × 2.1 mm column, with a mobile phase consisting of 0.1% formic acid in water and acetonitrile. Mass spectrometry used in a positive ionization mode and the transitions m/z 366.1 → 349.2 was selected to monitor amoxicillin, while m/z 370.1 → 114.15 was selected for the stable isotope labelled internal standard. This method features a linear quantification range of 10 ng/mL - 10 μg/mL, recovery of not less than 94.1%, a single sample extraction method for both plasma and milk matrices, and an analysis runtime of 5 min.