Development of an HPLC method for the determination of anidulafungin in human plasma and saline

An ultraviolet high-performance liquid chromatography (HPLC) method was developed to analyze anidulafungin in human plasma and saline. A reversed-phase column was used with a UV detector set at 310 nm. The mobile phase consisted of methanol and ammonium phosphate buffer at a flow rate of 1 mL/min. Micafungin was used as the internal standard. Both standard curves were linear over a range of 1 to 10 μg/mL. The intra-assay relative standard deviations (RSD) for plasma and saline matrices were 1.60-1.81% and 1.96-3.70%, respectively. The inter-assay RSD for plasma and saline matrices were 2.41-7.25% and 1.31-3.16%, respectively. This method successfully recapitulated anidulafungin plasma concentrations previously analyzed by HPLC-tandem mass spectrometry with precision and accuracy of 6.9% and 1.59%, respectively.