title: Determination of ampicillin in human plasma by solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) and its use in bioequivalence studies.
abstract: A simple, fast, sensitive and selective solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method for the quantitative analysis of ampicillin (CAS 69-53-4) in human plasma was developed using amoxicillin as internal standard, and sample extraction by solid-phase extraction (SPE). Extracts were separated by reversed-phase C18 with aqueous mobile phase (acetonitrile, 80:20, v/v) with 0.1% formic acid. The method was validated and successfully applied in a bioequivalence study of capsules 500 mg of ampicillin. Using a short running time of 2.5 min, the lower limit of quantification (LLOQ) for obtained ampicillin was 0.1 microg/ml for a plasma sample of 250 microl and a recovery of 94.38% +/- 4.05. Bioequivalence between the products was determined by calculating 90% confidence intervals (CI) for the ratio of Cmax, AUC0-t and AUC0-inf values for the test and reference products, which were within the 0.80-1.25 interval proposed by FDA and EMEA. It is concluded that the two formulations are bioequivalent in their rate and extent of absorption, and thus, may be used interchangeably.
authors.affiliation: NUDFAC-Núcleo de Desenvolvimento Farmacêutico e Cosmético, NUDFAC-UFPE, Centro de Biodisponibilidade / Bioequivalência, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Talita Mota
authors.initials: TM
authors.lastname: Gonçalves
authors.forename: Danilo César Galindo
authors.initials: DC
authors.lastname: Bedor
authors.forename: Luís Renato Pires
authors.initials: LR
authors.lastname: de Abreu
authors.forename: Carlos Eduardo Miranda
authors.initials: CE
authors.lastname: de Sousa
authors.forename: Clarice M Bueno
authors.initials: CM
authors.lastname: Rolim
authors.forename: Davi Pereira
authors.initials: DP
authors.lastname: de Santana
mesh_terms: D000293:Adolescent; D000328:Adult; D000658:Amoxicillin / Q000097:blood; D000667:Ampicillin / Q000097:blood* / Q000493:pharmacokinetics*; D000900:Anti-Bacterial Agents / Q000097:blood* / Q000493:pharmacokinetics*; D002138:Calibration; D002853:Chromatography, Liquid; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D011786:Quality Control; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D013810:Therapeutic Equivalency
chemical_list: D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D000667:Ampicillin; D000658:Amoxicillin