Potentiometric Flow Injection Analysis of Bromhexine Hydrochloride and its Pharmaceutical Preparation Using Conventional and Coated Wire Ion-Selective Electrodes

Bromhexine hydrochloride ion-selective electrodes (conventional type) based on bromhexinium tetraphenyl borate (I) and bromhexinium-phosphotungstate (II) were prepared. The electrodes exhibited mean slopes of calibration graphs of 59.4 mV and 59.8 mV per decade of bromhexine concentration at 25 C for electrode (I) and (II), respectively. Both electrodes could be used within the concentration range 3.16x10-1.00x10 M bromhexine within the pH range 2.0-4.5. The standard electrodes potentials were determined at different temperatures and used to calculate the isothermal coefficients of the electrodes, which were 0.00065 and 0.00050 V C for (I) and (II), respectively. The electrodes showed a very good selectivity for bromhexine with respect to a number of inorganic cations, amino acids and sugars. The electrodes were applied to the potentiometric determination of bromhexine hydrochloride and its pharmaceutical preparation under batch and flow injection conditions. Graphite, copper and silver coated wires were prepared, characterized and successfully applied as sensors for the drug under investigation.