A sensitive method for the simultaneous determination of loratadine and its major active metabolite descarboethoxyloratadine (DCL) in plasma was developed, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted from plasma with toluene followed by back-extraction into formic acid (2%) for DCL after which the toluene containing the loratadine was evaporated, the analyte reconstituted and combined with the DCL back-extract. Chromatography was performed on a Phenomenex Luna C18 (2) 5-microm, 150x2.1-mm column with a mobile phase consisting of acetonitrile-0.1% formic acid using gradient elution (10 to 90% acetonitrile in 2 min) at a flow-rate of 0.3 ml/min. Detection was achieved by a Perkin-Elmer API 2000 mass spectrometer (LC-MS-MS) set at unit resolution in the multiple reaction monitoring mode. TurbolonSpray ionisation was used for ion production. The mean recovery for loratadine and descarboethoxyloratadine was 61 and 100%, respectively, with a lower limit of quantification at 0.10 ng/ml for both the analyte and its metabolite. This is the first assay method described for the simultaneous determination of loratadine and descarboethoxyloratadine in plasma using one chromatographic run. The method is sensitive and reproducible enough to be used in pharmacokinetic studies.
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http://dx.doi.org/10.1016/s0021-9673(01)00646-x | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Department of Chemistry, Texas A&M University, PO Box 30012, College Station, TX 77842-30012.
The functionalization of pyridines at positions remote to the N-atom remains an outstanding problem in organic synthesis. The inherent challenges associated with overriding the influence of the embedded N-atom within pyridines was overcome using n-butylsodium, which provided an avenue to deprotonate and functionalize the C4-position over traditionally observed addition products that are formed with organolithium bases. In this work, we show that freshly generated 4-sodiopyrdines could undergo transition metal free alkylation reactions directly with a variety of primary alkyl halides bearing diverse functional groups.
View Article and Find Full Text PDFACS Chem Neurosci
January 2025
Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, Cracow 30-688, Poland.
The sodium-dependent membrane transporter SLC6A15 (BAT2) belongs to the SLC6 family, which comprises carriers of amino acids and monoamines. BAT2 is expressed in the central nervous system (CNS), including the glutaminergic and GABAergic system. SLC6A15 supplies neurons with neutral amino acids.
View Article and Find Full Text PDFBMC Pharmacol Toxicol
December 2024
Department of Pharmacy, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.
Background: H1-antihistamines are widely used to treat symptoms depending on histamine release in a variety of conditions. However, neurological adverse events have been reported in post-marketing surveillance studies and there are limited literatures comparing the neurological disorders associated with newer-generation H1-antihistamines from real-world datasets.
Aims: We performed a comparative analysis of nervous system disorders and several newer-generation H1-antihistamines including: cetirizine, loratadine, levocetirizine, desloratadine and fexofenadine.
Int J Nanomedicine
November 2024
Department of Pharmaceutics, College of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology, 6th of October City, Giza, Egypt.
Purpose: This study aims to prepare Loratadine-loaded chitosan/tannic acid nanoparticles (LOR-CS/TAN NPs) through ionic gelation to be used as an anti-proliferative agent to aid in overcoming breast cancer propagation.
Methods: First, in-silico virtual screening was carried out to select the most appropriate anti-histaminic drug based on its inhibitory effect on the H1-histamine receptor, resulting in the selection of Loratadine (LOR). Molecular interaction between LOR with chitosan (CS), a positively charged polymer, and hyaluronan, a negatively charged polymer, was investigated separately through molecular docking, leading to the selection of CS.
Front Immunol
November 2024
Department of Respiratory and Critical Care Medicine, Xi'an Jiaotong University Second Affiliated Hospital, Xi'an, China.
Background: Numerous studies have established that probiotics or prebiotics can relieve the symptoms of allergic rhinitis (AR), but their mechanism of action remain underexplored. This study aimed to observe the clinical efficacy of probiotics combined with prebiotics in seasonal AR patients and explore their underlying mechanisms.
Methods: We conducted a prospective, randomized, double-blind, placebo-controlled clinical trial.
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