Simultaneous square-wave voltammetric determination of acetazolamide and theophylline in pharmaceutical formulations

Abstract

Simple, rapid, sensitive and low cost voltammetric method for simultaneous determination of acetazolamide and theophylline in pharmaceutical formulations, was developed using a static mercury drop electrode (SMDE). Well-defined voltammetric peaks were obtained at-0.87 and-1.33 V for acetazolamide and-0.21 V (vs. Ag/AgCl) for theophylline in Britton-Robinson (B-R) buffer (pH 2.4). The reduction peak currents are found to be linearly dependent on the concentration for the both drugs. Calibration graphs were obtained over the concentration range 1.98 x 10(-6) to 5.94 x 10(-5) M and 2.0 x 10(-5) to 5.6 x 10(-4) M for acetazolamide and theophylline, respectively. The limits of detection (LOD) and quantitation (LOQ) of the procedure were also presented. Factors such as, pH of supporting electrolyte, equilibrium time, frequency, scan rate and pulse height were optimized. The validated voltammetric method was successfully applied for simultaneous determinations of the two drugs. The procedure does not require any sample pretreatment or timeconsuming separation steps.