Potentiometric sensors enabling fast screening of the benign prostatic hyperplasia drug alfuzosin in pharmaceuticals, urine and serum

The construction and characterization of potentiometric membrane electrodes are described for the quantification of alfuzosin, a drug used in a mono- and combined therapy of benign prostatic hyperplasia (BPH). The membranes of these electrodes consist of alfuzosin hydrochloride-tetraphenyl borate, (Az-TPB), chlorophenyl borate (Az-ClPB), and phosphotungstate (Az(3)-PT) ion associations as molecular recognition reagent dispersed in PVC matrix with dioctylpthalate as plasticizer. The performance characteristics of these electrodes, which were evaluated according to IUPAC recommendations, revealed a fast, stable and liner response for alfuzosin over the concentration ranges of 8.3 x 10(-6) to 1.0 x 10(-2) M, 3.8 x 10(-6) to 1.0 x 10(-2) M, 7.5 x 10(-7) to 1.0 x 10(-2) M AzCl with cationic slopes of 57.0, 56.0 and 58.5 mV/decade, respectively. The solubility product of the ion-pair and the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductometrically. The electrodes, fully characterized in terms of composition, life span and usable pH range, were applied to the potentiometric determination of alfuzosin hydrochloride ion in different pharmaceutical preparations and biological fluids without any interference from excipients or diluents commonly used in drug formulations. The potentiometric method was also used in the determination of alfuzosin hydrochloride in pharmaceutical preparations in four batches with different expiration dates. Validation of the method showed suitability of the proposed electrodes for use in the quality control assessment of alfuzosin hydrochloride. This potentiometric method offers the advantages of high-throughput determination, simplicity, accuracy, automation feasibility, and applicability to turbid and colored sample solutions.