title: Development and validation of a fast micro-extraction by packed sorbent UHPLC-PDA method for the simultaneous determination of linezolid and ciprofloxacin in human plasma from patients with hospital-acquired pneumonia.
abstract: An ultra high-performance liquid chromatographic (UHPLC) method with PDA detection was developed and validated for the simultaneous quantification of linezolid and ciprofloxacin in human plasma and applied in hospital acquired pneumonia patients (HAP). The method uses a semi-automated microextraction by packed sorbent for sample preparation. All parameters in the extraction step (pH, sample volume, sample dilution and number of aspiration - ejection cycles) and in the desorption step (percentage of acetonitrile in the solvent of elution and number of aspirations of elution solvent through the device) were statistically significant when the recovery was used as response. The method showed good linearity with correlation coefficients, r2>0.9995 for the two drugs, as well as high precision (RSD%<9.77% in each case), accuracy ranged from -6.2% to +8.2. The limit of quantification of the two drugs was established at 0.01 and 0.02μg/mL for ciprofloxacin and linezolid, respectively. Linezolid, ciprofloxacin and internal standard were extracted from human plasma with a mean recovery ranging from 92.4% to 97.4%. During validation, the concentrations of linezolid and ciprofloxacin were found to be stable after 3 freeze-thaw cycles and for at least 24h after extraction. This method will subsequently be used to quantify the drugs dosage in patients with HAP to establish if the dosage regimen given is sufficient to eradicate the infection at the target site.
authors.affiliation: Dipartimento di Farmacia, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ferrone
authors.affiliation: Dipartimento di Scienze Mediche Orali e Biotecnologiche, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
authors.forename: Maura
authors.initials: M
authors.lastname: Carlucci
authors.affiliation: Dipartimento di Scienze Mediche Orali e Biotecnologiche, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cotellese
authors.affiliation: Dipartimento di Scienze Mediche Orali e Biotecnologiche, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Raimondi
authors.affiliation: Dipartimento di Scienze Mediche Orali e Biotecnologiche, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
authors.forename: Annadomenica
authors.initials: A
authors.lastname: Cichella
authors.affiliation: Dipartimento di Farmacia, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
authors.forename: Lorenzo Di
authors.initials: LD
authors.lastname: Marco
authors.affiliation: Dipartimento di Farmacia, Università degli Studi "G. d'Annunzio" Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy. Electronic address: gcarlucci@unich.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Carlucci
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D002939:Ciprofloxacin / Q000097:blood* / Q000302:isolation & purification*; D003428:Cross Infection / Q000097:blood; D055615:Electrical Equipment and Supplies; D006801:Humans; D057230:Limit of Detection; D000069349:Linezolid / Q000097:blood* / Q000302:isolation & purification*; D011014:Pneumonia / Q000097:blood*; D052617:Solid Phase Microextraction / Q000379:methods*; D013997:Time Factors
chemical_list: D002939:Ciprofloxacin; D000069349:Linezolid
keywords: Ciprofloxacin; Human plasma; Linezolid; MEPS; Method validation; UHPLC-PDA; Ulifloxacin