title: Development of a liquid chromatography assay for the determination of opicapone and BIA 9-1079 in rat matrices.
abstract: Opicapone is a novel potent, reversible and purely peripheral third generation catechol-O-methyltransferase inhibitor, currently under clinical trials as an adjunct to levodopa therapy for Parkinson's disease. To support additional nonclinical pharmacokinetic studies, a novel high-performance liquid chromatographic method coupled to a diode array detector (HPLC-DAD) to quantify opicapone and its active metabolite (BIA 9-1079) in rat plasma and tissues (liver and kidney) is herein reported. The analytes were extracted from rat samples through a deproteinization followed by liquid-liquid extraction. Chromatographic separation was achieved in less than 10 min on a reversed-phase C18 column, applying a gradient elution program with 0.05 M monosodium phosphate solution (pH 2.45 ± 0.05) and acetonitrile. Calibration curves were linear (r(2)  ≥ 0.994) within the ranges of 0.04-6.0 µg/mL for both analytes in plasma, 0.04-4.0 µg/mL for opicapone in liver and kidney homogenates, and 0.07-4.0 µg/mL and 0.06-4.0 µg/mL for BIA 9-1079 in liver and kidney homogenates, respectively. The overall intra- and inter-day accuracy ranged from -12.68% to 7.70% and the imprecision values did not exceed 11.95%. This new HPLC-DAD assay was also successfully applied to quantify opicapone and BIA 9-1079 in a preliminary pharmacokinetic study.
authors.affiliation: Laboratory of Pharmacology, Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.|CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.
authors.forename: Daniela
authors.initials: D
authors.lastname: Gonçalves
authors.affiliation: CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.|CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506, Covilhã, Portugal.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Alves
authors.affiliation: Laboratory of Pharmacology, Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.|CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Fortuna
authors.affiliation: Department of Research and Development, BIAL, Av. da Siderurgia Nacional, 4745-457, S. Mamede do Coronado, Portugal.|Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal.
authors.forename: Patrício
authors.initials: P
authors.lastname: Soares-da-Silva
authors.affiliation: Laboratory of Pharmacology, Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.|CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.
authors.forename: Amílcar
authors.initials: A
authors.lastname: Falcão
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007668:Kidney / Q000737:chemistry; D016014:Linear Models; D008099:Liver / Q000737:chemistry; D008297:Male; D010069:Oxadiazoles / Q000032:analysis / Q000097:blood* / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010069:Oxadiazoles; C549349:opicapone
keywords: HPLC-DAD; catechol-O-methyltransferase inhibitor; method validation; opicapone; rat