title: Determination of impurities in propranolol hydrochloride by high-performance liquid chromatography on dynamically modified silica.
abstract: A rapid high-performance liquid chromatographic method has been elaborated for the separation and determination of small amounts of impurities in propranolol hydrochloride. The separation was achieved on a column of bare silica (Zorbax SIL) with methanol-water-0.2 M phosphate buffer pH 8.0 (70:25:5) containing 2.5 mM of cetyltrimethylammonium (CTMA) bromide as the eluent. The concentrations of methanol and CTMA as well as the pH of the phosphate buffer were found greatly to affect the separation. The selectivity of the system towards a mixture of propranolol and three possible impurities was investigated using different brands of silica. Only minor variations were found relative to those of a chromatographic system based on chemically bonded ODS silicas from the same sources. The method is also suitable for identification purposes, being able to separate most beta-blocking drugs of structures similar to that of propranolol.
mesh_terms: D002593:Cetrimonium Compounds; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004340:Drug Contamination; D006863:Hydrogen-Ion Concentration; D000432:Methanol; D011433:Propranolol / Q000032:analysis*; D012822:Silicon Dioxide
chemical_list: D002593:Cetrimonium Compounds; D012822:Silicon Dioxide; D011433:Propranolol; D000432:Methanol