title: Measurement of carbamazepine and its main biotransformation products in plasma by HPLC.
abstract: We present a method that permits the simultaneous analysis of carbamazepine (CBZ) and its major biotransformation products, carbamazepine-10,11-epoxide (CBZ-E) and carbamazepine-10,11-dihydroxide (CBZ-diOH), in plasma samples. The method consists of plasma extraction in alkaline medium with NaCl added using chloroform-ethyl acetate (1:1, v/v) and later purification with n-hexane. The samples were submitted to reversed-phase chromatography (RP-18) using acetonitrile-water (3:7, v/v) as the mobile phase and detection at 220 nm. Recoveries of 62.0, 99.9, and 105.4% were obtained for CBZ-diOH, CBZ-E, and CBZ, respectively, with sensitivities of 0.32 micrograms/mL for CBZ-E and CBZ-dOH and of 0.64 micrograms/mL for CBZ. The method proved to be specific, thus permitting measurements in situations of drug combinations.
authors.affiliation: Department of Physics, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: P S
authors.initials: PS
authors.lastname: Bonato
authors.forename: V L
authors.initials: VL
authors.lastname: Lanchote
authors.forename: D
authors.initials: D
authors.lastname: de Carvalho
authors.forename: P
authors.initials: P
authors.lastname: Achê
mesh_terms: D000293:Adolescent; D000328:Adult; D001711:Biotransformation; D002220:Carbamazepine / Q000031:analogs & derivatives* / Q000097:blood* / Q000493:pharmacokinetics; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D002220:Carbamazepine; C012227:carbamazepine epoxide