Abstract
Simple, precise, inexpensive and sensitive voltammetric methods have been developed for the determination of flavoxate HCl (FLXHC) and tolterodine tartrate (TOLT) in the bulk, pharmaceutical dosage forms and human urine using ferrocene modified carbon paste electrode (FMCPE) for FLXHC and polyethylene glycol modified carbon paste electrode (PEGMCPE) for TOLT. The electrochemical behavior of FLXHC and TOLT showed irreversible diffusion-controlled oxidation processes in Britton-Robinson (BR) buffer over the entire pH range from 2 to 6 for FLXHC and from 2 to 9 for TOLT. The peak current was evaluated as a function of some variables such as pH, scan rate and number of cycles of ferrocenium solution and PEG concentration. The linear ranges were 7.8 x 10(-6)-1.2 x 10(-4) mol L-1 and 7.6 x 10(-7)-2.2 x 10(-4) mol L-1 for FLXHC and TOLT, respectively. The limits of detection and quantification were 5.9 x 10(-7) and 2 x 10(-6) for FLXHC and 8.6 x 10(-8) mol L-1 and 2.9 x 10(-7) mol L-1 for TOLT. The percentage recoveries were found in the following ranges: 99.2-101.1% and 99.7-101.1% for FLXHC and TOLT, respectively. (C) 2016 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.