Sub- and supercritical fluid chromatography on packed columns: a versatile tool for the enantioselective separation of basic and acidic drugs.
Various chiral stationary phases were investigated in sub- and supercritical fluid chromatography for the separation, without derivatization, of basic (beta-blockers, benzodiazepines) and acidic (nonsteroidal anti-inflammatory drugs, beta-agonists) pharmaca. For all racemates, baseline separation was achieved within short analysis times. For several solutes, the high resolution obtained allowed injection of milligram amounts and semipreparative collection of the enantiomers. The parameters affecting enantioselectivity (column efficiency, influence of modifiers and basic or acidic additives, and temperature) have been studied. Enantiomerization of 3-OH-benzodiazepines could be suppressed by working at low temperatures or by using acetonitrile as a comodifier. Serial coupling of different chiral stationary phase columns resulted in a column triplet (Chiralpak AD, an amylose derivative; Chiralcel OD, a cellulose derivative; and Chirex 3022, a Brush-type with pi-donor characteristics) on which all solutes investigated could be baseline separated.
Department of Organic Chemistry, University of Ghent, Belgium.
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D000318:Adrenergic beta-Agonists / Q000737:chemistry / Q000302:isolation & purification; D000319:Adrenergic beta-Antagonists / Q000737:chemistry / Q000302:isolation & purification; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000302:isolation & purification; D001569:Benzodiazepines / Q000737:chemistry / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004364:Pharmaceutical Preparations; D001569:Benzodiazepines