Simultaneous determination of propacetamol and paracetamol by derivative spectrophotometry

A first-derivative spectrophotometric method for the simultaneous determina tion of propacetamol hydrochloride (PRO) and paracetamol (PA) is described, Measurements are made at the zero-crossing wavelengths at 242.0 for PRO an d 239.0 nm for PA. The calibration graphs were linear up to 20.0 and 15.0 m g l(-1) of PRO and PA, respectively, the limits of quantification were 0.75 and 0.46 mg l(-1). The possible interfering effects of other substances we re studied. The method was applied to determining the stability of PRO in e thanolic solutions and in glucose and saline parenteral solutions. (C) 2000 Elsevier Science B.V. All rights reserved.