title: Simultaneous determination of methyl, ethyl, propyl, and butyl 4-hydroxybenzoates and 4-hydroxybenzoic acid in liquid antacid formulations by gas chromatography.
abstract: An isothermal chromatographic (GC) method employing an SE-30 column and flame-ionization detection has been developed for the simultaneous assay of methyl, ethyl, propyl, and butyl 4-hydroxybenzoates and 4-hydroxybenzoic acid in liquid antacid formulations. The method, which uses a silica column chromatographic cleanup step prior to GC, is specific for the compounds with respect to possible degradation products, impurities, and excipients.
mesh_terms: D000863:Antacids / Q000032:analysis*; D002849:Chromatography, Gas / Q000379:methods; D004355:Drug Stability; D062385:Hydroxybenzoates / Q000032:analysis*; D011310:Preservatives, Pharmaceutical / Q000032:analysis
chemical_list: D000863:Antacids; D062385:Hydroxybenzoates; D011310:Preservatives, Pharmaceutical