title: Interlaboratory study of the analysis of ampicillin by liquid chromatography.
abstract: A liquid chromatographic method for the analysis of ampicillin was examined in a collaborative study involving seven laboratories. The method included an isocratic part, which is used in the assay. The isocratic part is similar to the assay method for ampicillin of the US Pharmacopeia XXIII Revision. When the isocratic part is combined with gradient elution, the method is suitable for purity control. Six samples of ampicillin (anhydrous, trihydrate and sodium salt) with varying purity were analysed. The main component and related substances were determined. An analysis of variance proved the absence of consistent laboratory bias. The laboratory-sample interaction was significant. Estimates of the repeatability and reproducibility of the method, expressed as standard deviations of the result of the determination of ampicillin, were calculated to be about 0.9 and 1.1 respectively.
authors.affiliation: Laboratorium voor Farmaceutische Chemie en Analyse van Geneesmiddelen, Faculteit Farmaceutische Wetenschappen, Leuven, Belgium.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: M L
authors.initials: ML
authors.lastname: Moreno
authors.forename: E
authors.initials: E
authors.lastname: Porqueras
authors.forename: E
authors.initials: E
authors.lastname: Bourke
authors.forename: A
authors.initials: A
authors.lastname: Bruzzi
authors.forename: M
authors.initials: M
authors.lastname: Aletrari
authors.forename: P
authors.initials: P
authors.lastname: Kanari
authors.forename: D
authors.initials: D
authors.lastname: Partasidou
authors.forename: J
authors.initials: J
authors.lastname: Nienhuis
authors.forename: W
authors.initials: W
authors.lastname: Ferigo
authors.forename: J L
authors.initials: JL
authors.lastname: Robert
authors.forename: J H
authors.initials: JH
authors.lastname: Miller
authors.forename: J M
authors.initials: JM
authors.lastname: Spieser
authors.forename: E
authors.initials: E
authors.lastname: Roets
authors.forename: J
authors.initials: J
authors.lastname: Hoogmartens
mesh_terms: D000667:Ampicillin / Q000032:analysis*; D000704:Analysis of Variance; D015982:Bias; D002853:Chromatography, Liquid; D010406:Penicillins / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D010406:Penicillins; D000667:Ampicillin