Abstract
A continuous flow spectrophotometric method for determining 0.5–100 μg ml
−1 of astemizole in pure and in dosage forms is suggested. It depends on forming a pinkish orange product which can be quantified spectrophotometrically at 495 nm. The coloured product was due to the action of
N-bromosuccinimide on astemizole in alkaline medium and in the presence of a cetyltrimethylammonium bromide micellar medium. The procedure is automated and solutions can be analysed at a rate of 167 h
−1 with a relative error of about 1.25%. The limit of detection is 0.5 μg ml
−1 (≈ 1.09 × 10
−6M). The method is evaluated by a recovery study and by the analysis of commercial formulations.