title: Determination of a process intermediate of celiprolol and its potential impurities by gradient high-performance liquid chromatography--application of high-low chromatography.
abstract: 3-(3-acetyl-4-hydroxyphenyl)-1,1-diethylurea (A-1354), is a synthetic intermediate of the beta-adrenergic blocker, celiprolol hydrochloride. A liquid chromatographic method has been developed and validated for the determination of bulk A-1354 and its potential impurities. High-low chromatography was used to improve the detectability of trace impurities. Enhanced chemical detectability was achieved by comparing the detector response of trace-impurity peaks from a stock sample solution (high-concentration) with the detector response for the A-1354 peak in a quantitatively diluted working sample solution (low-concentration). Chromatographic separation was achieved by gradient elution of A-1354 and its known impurities using an Ultrasphere C18 analytical column (5 microns, 250 x 4.6 mm i.d.). The gradient mobile phase components were methanol and 0.1% triethylammonium phosphate, pH = 4.0. The flow rate was 0.9 ml min-1 with UV absorbance detection at 236 nm. The method was determined to be specific, linear, precise and accurate for A-1354 and its known impurities. Known impurities of A-1354 are quantitated to 0.05% (w/w).
authors.affiliation: Department of Analytical and Physical Chemistry, Rhône-Poulenc Rorer Central Research, Fort Washington, PA 19034.
authors.forename: T J
authors.initials: TJ
authors.lastname: Difeo
authors.forename: J E
authors.initials: JE
authors.lastname: Shuster
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D015394:Molecular Structure; D010671:Phenylurea Compounds / Q000302:isolation & purification*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010671:Phenylurea Compounds; C075690:3-(3-acetyl-4-hydroxyphenyl)-1,1-diethylurea