Estimation of ipratropium bromide from aerosols by reversed-phase liquid chromatography

Ipratropium bromide, a derivative of N-isopropyl noratropine, was estimated from the samples of aerosols. An isocratic, reversed-phase liquid chromatographic separation method was developed by using an ODS, 5 μm column with the mobile phase acetonitrile-sodium dihydrogen orthophosphate (0.05M)-diethylamine (50 : 50 : 0.1, v/v) pH adjusted to 4.5 with phosphoric acid. Recoveries obtained were in the range 98% to 102% of ipratropium bromide from aerosol. Fluoxetine hydrochloride was used as an internal standard for quantitation.