title: A sensitive capillary LC-UV method for the simultaneous analysis of olanzapine, chlorpromazine and their FMO-mediated N-oxidation products in brain microdialysates.
abstract: A specific and sensitive capillary liquid chromatography-ultraviolet detection (cap-LC-UV) method in combination with a micro-extraction by packed sorbent (MEPS) sample clean-up procedure has been developed and validated for the simultaneous analysis of chlorpromazine, olanzapine and their flavin-containing monooxygenase (FMO) mediated N-oxides in rat brain microdialysates. Chromatographic separation was obtained on an Acclaim Pepmap RP C18 column with an ID of 300µm. An injection volume of 20µL was used to inject the largely aqueous samples and was shown to have no influence on the obtained peak shape of the compounds of interest. Optimal conditions for MEPS extraction were obtained on a mixed-mode M1 (80% C8, 20% SCX) cartridge after diluting microdialysate samples with phosphate buffer pH 2.5 (1:3 v/v). The method was validated and lower limits of quantification (LLOQ) were determined at 0.5nM for all compounds. Linearity was demonstrated between the LLOQ and 1µM for all compounds (R2>0.995). MEPS recoveries were between 92% and 98%, with intra- and interday variabilities below 15%. The applicability of the developed method was successfully demonstrated by analysing rat brain microdialysates. The capillary LC-UV method in combination with MEPS sample treatment provides a simple, sensitive method to quantify all compounds of interest in 45min and can be applied for routine therapeutic monitoring and pharmacokinetic studies of olanzapine, chlorpromazine and their respective N-oxides.
authors.affiliation: KU Leuven, Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium.
authors.forename: Stijn
authors.initials: S
authors.lastname: Hendrickx
authors.affiliation: Anadolu University, Faculty of Pharmacy, Department of Analytical Chemistry, 26470 Eskisehir, Turkey.
authors.forename: Duygu Yeniceli
authors.initials: DY
authors.lastname: Uğur
authors.affiliation: Anadolu University, Faculty of Pharmacy, Department of Analytical Chemistry, 26470 Eskisehir, Turkey.
authors.forename: Işil Tan
authors.initials: IT
authors.lastname: Yilmaz
authors.affiliation: Anadolu University, Faculty of Pharmacy, Department of Analytical Chemistry, 26470 Eskisehir, Turkey.
authors.forename: Erol
authors.initials: E
authors.lastname: Şener
authors.affiliation: KU Leuven, Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Van Schepdael
authors.affiliation: KU Leuven, Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium.
authors.forename: Erwin
authors.initials: E
authors.lastname: Adams
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, 1050 Brussel, Belgium.
authors.forename: Ken
authors.initials: K
authors.lastname: Broeckhoven
authors.affiliation: KU Leuven, Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium. Electronic address: deirdre.cabooter@kuleuven.be.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Cabooter
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000032:analysis / Q000493:pharmacokinetics; D001569:Benzodiazepines / Q000032:analysis* / Q000493:pharmacokinetics; D001921:Brain / Q000378:metabolism*; D002746:Chlorpromazine / Q000032:analysis* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015314:Dialysis Solutions / Q000737:chemistry*; D008297:Male; D017551:Microdialysis / Q000379:methods; D000077152:Olanzapine; D010084:Oxidation-Reduction; D010087:Oxides / Q000032:analysis; D010105:Oxygenases / Q000378:metabolism; D017208:Rats, Wistar; D015203:Reproducibility of Results
chemical_list: D014150:Antipsychotic Agents; D015314:Dialysis Solutions; D010087:Oxides; D001569:Benzodiazepines; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming); D000077152:Olanzapine; D002746:Chlorpromazine
keywords: Capillary LC; Chlorpromazine; FMO; MEPS; Microdialysis; Olanzapine