Voltammetric methods for electrochemical characterization and quantification of artemether-based antimalarials

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Pharmaceutical Analysis

Background:

• Substandard and falsified (SF) antimalarials cause significant mortality and economic loss globally.
• Limited pharmaceutical quality control infrastructure in low- and middle-income countries exacerbates the SF drug problem.
• Artemether, a crucial component of antimalarial drugs, requires reliable quantification methods.

Purpose of the Study:

• To evaluate the suitability of voltammetric methods for artemether identification and quantification.
• To assess the impact of excipients on artemether quantification.
• To develop and validate an electrochemical method for artemether analysis.

Main Methods:

• Cyclic voltammetry for electrochemical characterization of artemether.
• Chronocoulometry for artemether quantification.
• Analysis of pure artemether and Riamet® tablets (filtered and unfiltered).
• Investigation of pH effects and use of sodium sulfite to remove dissolved oxygen.

Main Results:

• Artemether exhibits chemically irreversible reduction between -0.4 V and -1.4 V.
• A chronocoulometric algorithm was successfully developed and tested.
• Filtration of Riamet® tablets did not improve artemether quantification.
• pH variations suggest protonation and coupled homogeneous chemistry.
• Sodium sulfite effectively improved artemether signal resolution in PBS.

Conclusions:

• Electrochemical analysis, particularly voltammetry, shows significant promise for the identification and quantification of artemether.
• The developed method is suitable for analyzing artemether in pharmaceutical formulations.
• This approach could aid in combating substandard antimalarial drugs.