Voltammetric determination of vildagliptin in a pharmaceutical formulation

Muneer Fadr,Sami Ben Aoun,Abdulaziz Nabil Amro

doi:10.4314/tjpr.v17i9.24

Abstract

Purpose: To determine vildagliptin concentration in a pharmaceutical formulation using voltammetric analysis techniques, and optimize the parameters affecting the techniques. Method: Four types of voltammetry techniques, including cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and linear sweep voltammetry (LSV), were employed to measure vildagliptin. Platinum (Pt) and glassy carbon (GC) were used as working electrodes, while KNO 3 (1 M) and phosphate buffer (NaH 2 PO 4 /H 3 PO 4 ) pH 6.8 were used to study optimal voltammetric analysis conditions. Results: CV results indicate that vildagliptin is electroactive and exhibits irreversible redox cycles while LSV results showed an oxidation peak current around 1.35 V that has high sensitivity and a linear standard regression line correlation coefficient of 0.9995. In addition, LSV results showed that vildagliptin has a lower limit of detection of ~ 0.241 mM and a limit of quantification of ~ 0.802 mM. Finally, the results show that vildagliptin has an acceptable level of recovery of 104.1 % and a relative standard deviation of 0.52 % for the commercially available vildagliptin tablets used in this study. Conclusion: The accuracy and precision of all applied voltammetric techniques for vildagliptin analysis are within accepted limits stipulated in pharmaceutical analysis quality control guidelines. The recommended method for vildagliptin analysis is LSV with Pt as the working electrode and KNO 3 (1 M) as the supporting electrolyte. Keywords: Vildagliptin, Cyclic voltammetry, Square wave voltammetry, Differential pulse voltammetry, Linear sweep voltammetry

Highlights

Chromatography, spectrophotometry, and electrochemistry have traditionally been considered the most commonly used methods in pharmaceutical analyses [1]
Cyclic voltammetry was used to study the electroactivity of pure vildagliptin
Voltammograms show that vildagliptin was electroactive with an irreversible redox cycle and anodic peak current in the range of 1.25 – 1.45 V when Pt was used as the working electrode and KNO3 was used as the supporting electrolyte

Summary

INTRODUCTION

Chromatography, spectrophotometry, and electrochemistry have traditionally been considered the most commonly used methods in pharmaceutical analyses [1]. We choose to use more accurate electrochemical voltammetric analysis technique for the determination of vildagliptin in a pharmaceutical formulation. The experimental parameters affecting the used technique, such as types of working electrodes and supporting electrolytes, were optimized. GulvusTM tablets were weighed and ground by mortar and pestle, and a certain mass was dissolved in the supporting electrolyte solution. Stock standard solutions were prepared by dissolving solid vildagliptin in supporting electrolyte solutions. Supporting electrolytes were used to dilute the stock solution to prepare the working standard solutions. The standard pharmaceutical formulation (pure powder) of vildagliptin was obtained from CAD Pharmaceuticals (Saudi Arabia). Standard Stock solutions of 10 mM were prepared from pure vildagliptin powder; All voltammetric analysis data have been processed by Microsoft excel software.

RESULTS

DISCUSSION

Method

CONCLUSION

Conflict of Interest