Simultaneous determination of maltol and maltol glucuronide in human plasma and urine by HPLC–MS/MS: Application in clinical study in patients with iron deficiency

Ferric maltol has been used as an oral drug for iron deficiency. This study developed and fully validated the novel HPLC–MS/MS methods to determine maltol and maltol glucuronide simultaneously in plasma and urine. The protein precipitation was performed by addition of acetonitrile in the plasma samples. The dilution was performed for the urine samples to reach the suitable concentrations for injection. The multiple reaction monitoring (MRM) with an electrospray ionization (ESI) positive ion detection mode was used for the quantification. The maltol concentration linear ranges were 6.00–150 ng/mL and 0.100–10.0 μg/mL for the plasma and urine samples, respectively. The maltol glucuronide concentration linear ranges were 50.0–15000 ng/mL and 2.00–2000 μg/mL for the plasma and urine samples, respectively. These methods were applied to a single dose clinical study at a dose of 60 mg ferric maltol capsule in the patients with iron deficiency. The half-lives of maltol and maltol glucuronide were 0.90 ± 0.40 h and 1.02 ± 0.25 h in the iron deficiency patients, respectively. 39.52 ± 7.11 % maltol were excreted in urine in the form of maltol glucuronide.