Electrochemical performance of screen printed sensors for potentiometric determination of anticholinergic oxybutynine hydrochloride in pharmaceutical formulations and biological fluids.

Abstract

N EW potentiometric sensitive and selective modified screen printed electrodes (MSPE) which based on phosphotungestic acid (PTA), sodium tetraphenyl borate (NaTPB), phosphomolybdic acid (PMA) or ammonium reineckate (RN) ion pairing agents for determination of oxybutynine hydrochloride (OBCH) were developed. The proposed electrodes have Nernstian slope values of 59.200.52±, 58.000.22± and 58.520.22± mV decade-1 for electrodes modified with 7.5, 17.5 and 7.5 mg of RN (electrode I), NaTPB (electrode II) and PTA (electrode III) ion pairing agents, respectively. It is found that the dynamic drug concentration range at 25 °C was 1.0x10-5-1.0x10-2 mole L-1 with detection limit (LOD) equal 1.0× 10-5 mol L-1 and limit of quantification (LOQ) equal 3.33×10-5 mol L-1. The response of MSPEs was pH independent in the range 2.0-6.0. The investigated electrodes have fast response time of 10, 9 and 8 s for electrodes I, II and III, respectively. These electrodes have good Nernstian response in the temperature range 10-60 °C. The slope of the straight-line obtained represented the isothermal coefficient of MSPEs which were found to be 1.594 ×10-3 , 2.151×10-3 and 2.377×10-3 V/ for electrodes I, II and III, respectively. The small values of the isothermal coefficient indicated the high thermal stability of the electrodes. The MSPEs showed a relatively long life time of 36 days. Pure, biological fluids and pharmaceutical formulation of OBCH were quantified using calibration and standard addition methods and the obtained results agreed with that of the official HPLC method. Validation parameters were optimized according to ICH recommendations.

Modified carbon paste ion selective electrode for determining Cr(iii) ions in aqueous solutions and some real samples using tetragonal zirconia nanoparticles

“…They strengthen the mechanical connections between the various electroactive carbon particles to establish a consistent, compact combination. 4,15,16 In accordance with the plasticization's lubricating hypothesis, the plasticizer molecules dispersed throughout the polymer and diminished the contacts (van der Waals forces). This enables the chains to pass each other speedily and leads to exibility, soness, and elongation.…”

“…The black paste is homogeneously ground with 0.250 g, (5,10,15) mg, and 0.12 g of graphite powder, t-ZrO 2 -NPs, and plasticizer, respectively, which are mixed in a mortar and pestle. The mixture was gently stuffed into the electrode's tube over one side then le there for 24 hours in distilled water to obstruct air intrusion.…”

“…4,12 Ion concentrations in various substances can now be directly determined potentiometrically using ion-selective electrodes (ISEs). 4,[13][14][15][16] One of the extremely important ISE is modied carbon pastebased sensors (MCPEs) which formed from blending of pasting liquid (plasticizer), conductive graphite powder and ion carrier and offer a lot of merits include being simple to apply to colored and turbid liquids, affordable, providing satisfactory selectivity, having a minimal detection limit, possessing outstanding accuracy, and offering a wide concentration range. The ion carrier employed in the MCPE determines all of these benets.…”

“…4,12 Ion concentrations in various substances can now be directly determined potentiometrically using ion-selective electrodes (ISEs). 4,13–16…”

Potentiometric determination of mepivacaine hydrochloride local anesthetic drug in pharmaceutical and biological fluids using ion selective electrode

“…The method was validated for linearity, lower limit of detection, precision, accuracy, robustness and ruggedness in accordance with ICH guidelines [42,43].…”