A Comparative Study between Screen-Printed and Solid-Contact Electrodes for the Stability-Indicating Determination of...

Area of Science:

• Electroanalytical Chemistry
• Pharmaceutical Analysis

Background:

• Stability-indicating methods are crucial for ensuring the safety and efficacy of active pharmaceutical ingredients (APIs).
• Accurate determination of APIs like bromazepam (BRZ) in the presence of impurities and degradation products is essential for quality control.

Purpose of the Study:

• To develop and compare two novel potentiometric sensors for the accurate determination of bromazepam.
• To evaluate the sensors' performance in quantifying BRZ in the presence of its main degradation product and impurity.
• To assess the applicability of the sensors for BRZ quantification in pharmaceutical formulations.

Main Methods:

• Fabrication and optimization of two membrane electrodes: a screen-printed electrode (SPE) and a solid-contact glassy carbon electrode (SCE).
• Electrochemical characterization of the sensors, including linearity, Nernstian response, and pH influence.
• Validation of the sensors for quantifying BRZ in the presence of degradation products and in tablet formulations.

Main Results:

• Both BRZ-SPE and BRZ-SCE sensors exhibited a linear electrochemical response from 1.0 × 10⁻⁶ M to 1.0 × 10⁻² M.
• Nernstian slopes of 59.70 mV/decade (BRZ-SPE) and 58.10 mV/decade (BRZ-SCE) were achieved.
• Optimal performance was observed between pH 3.0 and 6.0, with successful quantification of BRZ even with up to 90% degradation product and in tablet form without pretreatment.

Conclusions:

• The developed potentiometric sensors (BRZ-SPE and BRZ-SCE) offer a sensitive, selective, and accurate method for bromazepam determination.
• These sensors are effective in quantifying BRZ in complex matrices, including samples with significant degradation products and in pharmaceutical formulations.
• The study highlights the potential of these novel sensors as valuable tools for stability-indicating assays in pharmaceutical quality control.