{'fraction_non_alphanumeric': 0.04464871963230466, 'fraction_numerical': 0.03217334208798424, 'mean_word_length': 4.976470588235294, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A bio-analytical hydrophilic interaction LC-MS/MS method for the simultaneous quantification of omeprazole and lansoprazole in human plasma in support of a pharmacokinetic omeprazole study in children.

A hydrophilic interaction LC method with MS/MS was developed and validated for the simultaneous quantification of omeprazole and lansoprazole in human plasma. Chromatographic separation was achieved on a Betasil silica column using a high organic mobile phase (eluent A: ACN/formic acid 997.5:2.5 v/v; eluent B: water/formic acid 997.5:2.5 v/v) and gradient elution. The mass spectrometer was operated in the Multiple Reaction Monitoring mode. Prior to chromatography, liquid-liquid extraction with ethyl acetate was used and the organic layer was diluted with ACN, allowing direct injection on column. The method showed acceptable linearity, high precision (RSD%<10.5%), accuracy (88.9-109.3%) and selectivity in the two concentration ranges studied: 1.5-100 and 5-2000 ng/mL. The LOQ was established at 1.5 and 5 ng/mL for the two concentration ranges. Lack of variability in matrix effects was demonstrated and mean extraction recovery for omeprazole and lansoprazole was determined in the low (56.3-67.7%) and high (45.3-44.3%) concentration range, respectively. Additionally, plasma samples were found to be stable after three freeze-thaw cycles and for at least 15 h after extraction. This assay was successfully applied to a pharmacokinetic omeprazole study in children with cerebral palsy and mental retardation.