Sibutramine selective electrodes for batch and flow injection determinations in pharmaceutical preparations

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Materials Science

Background:

• Sibutramine hydrochloride is a widely used drug, necessitating reliable analytical methods for its quantification.
• Existing methods for sibutramine hydrochloride determination may lack the sensitivity or speed required for certain applications.
• Development of novel electrochemical sensors can provide efficient and cost-effective analytical solutions.

Purpose of the Study:

• To construct and characterize two novel polyvinyl chloride (PVC) membrane sensors for sibutramine hydrochloride.
• To evaluate the electrochemical performance of these sensors, including response time, stability, and detection limits.
• To assess the applicability of the developed sensors for sibutramine hydrochloride determination in pharmaceutical products.

Main Methods:

• Fabrication of PVC membrane sensors incorporating ion-association complexes of sibutramine with sodium tetraphenylborate (NaTPB) or phosphotungstic acid (PTA).
• Utilizing dibutyl phthalate as a plasticizing solvent in the sensor membranes.
• Electrochemical characterization using potentiometric measurements to determine sensor response, linearity, and detection limits.
• Application of the sensors in both batch and flow injection (FI) analysis for real-world sample analysis.

Main Results:

• The developed sensors exhibited fast and stable responses for sibutramine hydrochloride over a concentration range of 3.84 x 10(-5) to 1.00 x 10(-2) M.
• Cationic slopes of 57.7 ± 0.57 and 59.7 ± 1.79 mV/concentration decade were achieved.
• Detection limits were determined to be 8.91 x 10(-6) M for the Sibu-TPB sensor and 1.47 x 10(-5) M for the (Sibu)(3)-PT sensor.
• Successful application of the sensors for sibutramine hydrochloride determination in Regitrim capsules under both batch and FI conditions.

Conclusions:

• The newly developed PVC membrane sensors based on sibutramine-ion association complexes are effective for the determination of sibutramine hydrochloride.
• These sensors offer good sensitivity, selectivity, and operational stability.
• The proposed sensors provide a viable analytical tool for quality control of sibutramine hydrochloride in pharmaceutical formulations.