title: Packed-column supercritical fluid chromatography for the purity analysis of clevidipine, a new dihydropyridine drug.
abstract: In this paper we describe a packed column supercritical fluid chromatography method that can be used for the analysis of a new dihydropyridine substance. The method is based on methanol-modified carbon dioxide as the mobile phase and Hypersil bare silica as column support at a column temperature of 50 degrees C and 150 bar as back pressure. Using an adjusted methanol gradient the most likely by-products can be separated and detected (240 nm) within 13 min. Occasionally the column needed treatment with 4 mM citric acid in the methanol modifier in order to give a narrow peak of an acidic analogue. The present method can detect analogues at the 0.1% (w/w) level. The precision at this level for one of the analogues was 5.9% RSD. This method shows a higher selectivity than a corresponding reversed-phase liquid chromatographic method.
authors.affiliation: Department of Analytical Chemistry, AstraZeneca R&D Mölndal, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Gyllenhaal
authors.forename: A
authors.initials: A
authors.lastname: Karlsson
authors.forename: J
authors.initials: J
authors.lastname: Vessman
mesh_terms: D000959:Antihypertensive Agents / Q000032:analysis* / Q000302:isolation & purification*; D002853:Chromatography, Liquid / Q000379:methods*; D011725:Pyridines / Q000032:analysis* / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide
chemical_list: D000959:Antihypertensive Agents; D011725:Pyridines; C118563:clevidipine; D012822:Silicon Dioxide