Analytical Eco-Scale for Evaluating the Greenness of Advanced Voltammetric Method Used for the Simultaneous Analysis of Combined Urinary Tract Infection Drugs in Different Matrices

Phenazopyridine hydrochloride (PHZ) and Trimethoprim (TMP) are formulated together to treat urinary tract infections. The present work represents the first electrochemical sensor to simultaneously determine Phenazopyridine hydrochloride (PHZ) and Trimethoprim (TMP) with good anodic peak potential separation. A rapid, simple and sensitive electrochemical oxidation based on using multiwalled carbon nanotubes (CNT) and sugar polymer (PS) as modifier carbon paste (CNT/PS/MCPE) is described. The method was developed and validated in accordance with the guidelines of the International Council for Harmonisation (ICH). With a detection limit of 2 × 10 −7 M to 1 × 10 −4 M for both drugs with good recovery in pH 7. The method was then efficiently applied to determine PHZ and TMP in pharmaceutical formulation, human serum and urine. The proposed voltammetric method was statistically compared with the reported spectrophotometric method and the results obtained indicate no significant differences. Moreover, the fabricated sensor was applicable for the determination of PHZ and TMP in presence of common interfering molecules, ascorbic acid (AA) and uric acid (UA) which can be present in the plasma and urine. The method proved to be an excellent green analysis according to analytical eco-scale for greenness assessment.