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Validated ion pair liquid chromatography/fluorescence detection method for assessing the variability of the loratadine metabolism occurring in bioequivalence studies
Author(s) -
Sora Daniela Iuliana,
Udrescu Stefan,
David Victor,
Medvedovici Andrei
Publication year - 2007
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/bmc.845
Subject(s) - chemistry , chromatography , loratadine , analyte , bioequivalence , sample preparation , detection limit , diethyl ether , ion suppression in liquid chromatography–mass spectrometry , mass spectrometry , fluorescence , sodium dodecyl sulfate , fluorescence spectroscopy , elution , analytical chemistry (journal) , liquid chromatography–mass spectrometry , pharmacokinetics , medicine , physics , quantum mechanics , anesthesia
Inter‐ and intra‐individual variability of the loratadine (LOR) metabolism in Caucasian subjects was assessed during a bioequivalence study for two pharmaceutical formulations (solid oral dosage forms) containing 10 mg of the active substance. The analytical data were obtained by applying a reliable, low‐cost and sensitive ion pair liquid chromatography/fluorescence (IPLC/FLD) method for determination of both loratadine and descarboethoxyloratadine (DCL) in human plasma samples. The sample preparation procedure is based on liquid–liquid extraction of the target analytes from alkalinized plasma using diethyl‐ether. The separation of the analytes and 8‐chloroazatadine as internal standard (IS) was achieved through an isocratic ion pair (IP) elution on a Purospher ® STAR RP‐18 column. The mobile phase containing sodium dodecyl sulfate (SDS) as ion pairing agent was pumped at a flow rate of 1 mL/min. Fluorescence detection (FLD) was achieved at 280 nm (excitation) and 440 nm (emission) wavelengths. The increased sensitivity of the method is also based on a large sample injected volume (250 µL). Linear response was found over the 0.5–20 ng/mL concentration interval for both target compounds. Low limits of quantification (LLOQ) around 0.3 ng/mL were found for LOR and DCL. Method validation is presented. Copyright © 2007 John Wiley & Sons, Ltd.