Kinetic determination of propranolol in drug formulations

Abstract

A kinetic method for the accurate determination of propranolol has been developed. A solution of propranolol is heated with 2.72 × 10^–2M potassium dichromate in 5 M sulphuric acid at 90 °C for a fixed time of 20 min, after which the reaction is quenched by cooling and the absorbance of the coloured chromium(III) species produced is measured at 590 nm. The concentration of propranolol is calculated by using the corresponding calibration equation for the fixed-time method. The method has been applied to proprietary drugs and the results were compared statistically with those given by the BP method. The determination of propranolol by the fixed-concentration and rate-constant methods is feasible with the calibration equations obtained but the fixed-time method has been found to be more applicable.