Determination of landiolol in human plasma by high-performance liquid chromatography with fluorescence detection

Landiolol is an ultra-short-acting β ₁-adrenergic receptor-blocking agent that is used with perioperative patients who are at risk of cardiac events. The drug is hydrolyzed very rapidly by pseudocholinesterase in the blood. Using physostigmine (final concentration: 10 ^-4 mol/L) as a cholinesterase inhibitor, we developed a simple and rapid quantification method for landiolol using high-performance liquid chromatography. Chromatographic separations were achieved on a C ₁₈ column with 20 mMKH ₂PO ₄/acetonitrile (70/30, v/v). Propranolol was used as an internal standard. The peaks were detected using a fluorescence detector (excitation 220 nm and emission 310 nm). The retention times of landiolol and propranolol were 5.6 min and 6.7 min, respectively. The lower limit of quantification was estimated as being 0.1 μg/mL. The precision of the inter-and intra-assay varied between 1.8% and 12.6%, and the accuracy varied between-8.1% and 7.7%. This method was useful for the determination of landiolol in human plasma after intravenous administration.