title: Quality control of metoprolol extended-release formulations in the presence of ethanol.
abstract: This paper presents in-vitro metoprolol release from four different extended-release (ER) formulations, i.e. Metoprolol GEA® Retard, Logimax® forte, Metoprolol Sandoz® and Seloken ZOC® in the presence of 10 to 40% (v/v%) ethanol at pH 1.2 and pH 6.8. The assay of metoprolol in the dissolution media was performed by reversed phase liquid chromatography (RP-LC) using a mixture of methanol and 100 mM phosphate buffer (pH 3.5) in 40:60 ratio as eluent. The dissolution data showed that the metoprolol contents of Metoprolol Sandoz® and Seloken ZOC® were released fast in the presence of 20% ethanol at the investigated conditions, while the other products demonstrated much more stability against ethanol. Unexpectedly it was discovered that the release of metoprolol from Metoprolol GEA® Retard and to some extent also from Logimax® forte decreased in the ethanol containing media.
authors.affiliation: Medical Products Agency, P.O. Box 26, SE-751 03 Uppsala, Sweden. ahmad.amini@mpa.se
authors.forename: A
authors.initials: A
authors.lastname: Amini
authors.forename: A
authors.initials: A
authors.lastname: Dawood
authors.forename: A-M
authors.initials: AM
authors.lastname: Hesselgren
authors.forename: H
authors.initials: H
authors.lastname: Thor
authors.forename: S
authors.initials: S
authors.lastname: Jönsson
authors.forename: T
authors.initials: T
authors.lastname: Arvidsson
authors.forename: G
authors.initials: G
authors.lastname: Ragnarsson
authors.forename: M
authors.initials: M
authors.lastname: Johansson
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists / Q000592:standards*; D003692:Delayed-Action Preparations; D000431:Ethanol / Q000737:chemistry*; D008790:Metoprolol / Q000008:administration & dosage / Q000737:chemistry / Q000592:standards*; D011786:Quality Control; D012995:Solubility
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D003692:Delayed-Action Preparations; D000431:Ethanol; D008790:Metoprolol