Sensing of chlorpheniramine in pharmaceutical applications by sequential injector coupled with potentiometer

Abstract

This paper reports on development of a system consisting of a portable sequential injector coupled with potentiometric unit for sensing of chlorpheniramine (CPA), based on the reaction of CPA with potassium permanganate in acidic media. Various experimental conditions affecting the potential intensity were studied and incorporated into the procedure. Under the optimum conditions, linear relationship between the CPA concentration and peak area was obtained for the concentration range of 0.1-50 ppm. The method reflects good recovery with relative standard deviation (RSD)<3%. The detection limit was 0.05 ppm. The developed method was successfully applied for determination of CPA in pure form and in pharmaceutical dosage forms. The results, obtained using the method, are in accord with the results of the British pharmacopoeia method. In addition to its accuracy and precision, the method has the advantages of being simple, inexpensive and rapid.

Keywords: Chlorpheniramine; Flow injection; Potentiometry; Sensing.

Figure 1

Chemical structure of chlorpheniramine maleate.

Figure 2

Schematic representation of the system used for sensing of chlorpheniramine with; H₂SO₄: carrier, SP: syringe pump, PP: peristaltic pump, MV: multiselection valves, S: sample; AC: current source, D: electrode detector, DA: digital-to-analog converter, PC: Readout desktop computer.

Figure 3

The influence of flow rate on the peak intensity. Conditions: CPA concentration 1 ppm; CPA volume 110 μL; potassium permanganate 0.001 mol/L, 100 μL; current density 10 μA/cm² ; delay time 20 s; coil length 20 cm.

Figure 4

The influence of delay time on the peak intensity. Conditions: CPA concentration 1 ppm; CPA volume 110 μL; potassium permanganate 0.001 mol/L, 100 μL; current density 10 μA/cm²; flow rate 40 μL/s; coil length 20 cm.

Figure 5

The influence of coil length on the peak intensity. Conditions: CPA concentration 1 ppm; CPA volume 110 μL; potassium permanganate 0.001 mol/L, 100 μL; current density 10 μA/cm²; flow rate 40 μL/s; delay time 15 s.

Figure 6

Represents repeated measurements of CPA by the proposed method. Conditions: CPA concentration 1 ppm; CPA volume 110 μL; potassium permanganate 0.001 mol/L, 100 μL; current density 10 μA/cm²; flow rate 40 μL/s; delay time 15 s; coil length 20 cm.

Figure 7

The signal response to different chlorphenireamine concentartions; 0.1, 0.5, 1, 5, 10, 20, 30, 40 and 50 ppm. Other conditions are: CPA volume 110 μL; potassium permanganate 100 μL; current density 10 μA/cm²; delay time 15 s; coil length 20 cm; flow rate 40 μL/s.