A Novel Polymeric Membrane Sensor for Chlorhexidine Determination

Area of Science:

• Electroanalytical Chemistry
• Sensing Technology
• Pharmaceutical Analysis

Background:

• Accurate determination of chlorhexidine (CHXD) is crucial for pharmaceutical quality control.
• Existing methods for CHXD quantification may lack sensitivity or speed.
• Development of novel potentiometric sensors offers a promising alternative for rapid analysis.

Purpose of the Study:

• To develop and optimize a potentiometric sensor for the determination of chlorhexidine (CHXD).
• To investigate the performance of polymer membranes incorporating cyclodextrins and ion exchangers.
• To validate the sensor's efficacy in analyzing pharmaceutical formulations containing CHXD.

Main Methods:

• Fabrication of polymer membrane electrodes plasticized with DOS or o-NPOE.
• Incorporation of active compounds like cyclodextrins, crown ethers, and ion exchangers.
• Optimization of electrode composition, focusing on heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin and KTpClBP.

Main Results:

• The optimized sensor exhibited a cationic slope of 30.9 ± 2.9 mV decade⁻¹ within a linear range of 1 × 10⁻⁶ to 1 × 10⁻³ mol L⁻¹.
• The sensor demonstrated a fast response time (5s for increasing concentration, 10s for dilution) and stable potential over a pH range of 4.0-9.5.
• Successful application in pharmaceutical samples with high accuracy (RSD = 0.3-1.1%) and low relative error (1.1%).

Conclusions:

• A highly sensitive and selective potentiometric sensor for CHXD determination was successfully developed.
• The sensor based on a specific cyclodextrin derivative offers excellent performance characteristics.
• The developed sensor is suitable for the reliable quantification of chlorhexidine digluconate in pharmaceutical products.