title: Validation of a UPLC-MS/MS method for the simultaneous determination of E6005, a phosphodiesterase 4 inhibitor, and its metabolite in human plasma.
abstract: E6005, a novel phosphodiesterase 4 inhibitor, is currently under clinical development for the treatment of atopic dermatitis. As ER-392710 (M11), a hydrolyzed metabolite, is a main metabolite, a simultaneous assay method for quantification of E6005 and M11 in human plasma has been developed and validated using ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS). E6005, M11, and each deuterium-labeled compound used as internal standard were extracted from 100μL human plasma by solid phase extraction then chromatographed on an Acquity UPLC BEH C18 column (100mm×2.1mm i.d., 1.7μm) under gradient elution. The analytes were detected by selected reaction monitoring in the positive ion mode with the mass transition of m/z 473.1/163.0 and m/z 459.1/149.0 for E6005 and M11, respectively. E6005 and M11 were quantifiable ranging from 1 to 200ng/mL with no carryover. Accuracy and precision in intra- and inter-batch reproducibility assays were within the acceptance criteria recommended by the regulatory bioanalytical guidelines. Various stability assessments including possible conversion of E6005 to M11 were thoroughly performed to demonstrate the stability of E6005 and M11 in human blood and plasma. The method was successfully applied to support clinical trials.
authors.affiliation: Drug Metabolism and Pharmacokinetics, Biopharmaceutical Assessment Core Function Unit, Eisai Co., Ltd., 1-3, 5-chome, Tokodai, Tsukuba-shi, Ibaraki 300-2635, Japan. Electronic address: y2-mano@hhc.eisai.co.jp.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mano
authors.affiliation: Bioanalysis Unit, Tsukuba R&D Supporting Division, Sunplanet Co., Ltd., 1-3, 5-chome, Tokodai, Tsukuba-shi, Ibaraki 300-2635, Japan.
authors.forename: Takuho
authors.initials: T
authors.lastname: Ishii
authors.affiliation: Drug Metabolism and Pharmacokinetics, Biopharmaceutical Assessment Core Function Unit, Eisai Co., Ltd., 1-3, 5-chome, Tokodai, Tsukuba-shi, Ibaraki 300-2635, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Hotta
authors.affiliation: Drug Metabolism and Pharmacokinetics, Biopharmaceutical Assessment Core Function Unit, Eisai Co., Ltd., 1-3, 5-chome, Tokodai, Tsukuba-shi, Ibaraki 300-2635, Japan.
authors.forename: Kazutomi
authors.initials: K
authors.lastname: Kusano
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D010795:Phthalic Acids / Q000097:blood* / Q000302:isolation & purification / Q000378:metabolism; D011799:Quinazolines / Q000097:blood* / Q000302:isolation & purification / Q000378:metabolism; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010795:Phthalic Acids; D011799:Quinazolines; C583128:methyl 4-(((3-(6,7-dimethoxy-2-(methylamino)quinazolin-4-yl)phenyl)amino)carbonyl)benzoate
keywords: Atopic dermatitis; E6005; UPLC–MS/MS; Validation