Liquid chromatography-mass spectrometry determination of iloperidone on rat dried blood spots: application to pharmacokinetics

Abstract

A simple, rapid and highly sensitive liquid chromatography-mass spectrometry method was developed and validated for analysis of iloperidone on rat dried blood spots. The chromatographic separation was achieved on an Agilent RP-18 column (250 × 4.6 mm; 5 μm), using 20 mM ammonium acetate (adjusted to pH 5 with TFA) and acetonitrile (60 : 40 v/v) as a mobile phase at a flow rate of 1.0 mL min⁻¹ in an isocratic mode. The analytes were detected in positive electrospray ionization mode and monitored selectively at m/z 427 [M + H]⁺ for iloperidone and paliperidone used as an internal standard. The mean recovery of iloperidone from dried blood spots was 95.7% with an intra- and inter-day precision of 9.6%. The assay was linear over a range of 1–300 ng mL⁻¹. The limits of detection and quantification were found to be 0.09 ng mL⁻¹ and 0.3 ng mL⁻¹ respectively. Stability studies showed that iloperidone was stable on dried blood spots for 1 month at −20 °C. The effect of hematocrit to assess the accuracy of extraction of iloperidone from dried blood spots was evaluated and found to be more than 94%. The developed method was applied to study the pharmacokinetics of iloperidone by an oral administration of 5 mg kg⁻¹ in healthy rats.