DIRECT KINETIC DETERMINATION OF BROMHEXINE HYDROCHLORIDE IN PHARMACEUTICAL FORMULATIONS

A very simple, automatic, fast method for the photometric determinatio n of bromhexine hydrochloride based on the application of kinetic meth odology and the stopped-flow mixing technique to the coupling reaction between the diazotized bromhexine derivative and (N-(1-naphthyl)ethyl enediamine is proposed. The high initial rate of this reaction allows analytical measurements to be made within only 0.5-1 s, which makes th e method applicable to automatic routine analyses. The calibration gra ph is linear over the range 1.5-65.0 mug mL-1 and the precision (as %R SD) is less than 2%. The presence of antibiotics such as penicillins a nd cephalosporins in a 100-fold excess has no effect on the analyte de termination. The proposed method was satisfactorily used for direct an alysis of pharmaceutical formulations containing these antibiotics.