RESUMEN
BACKGROUND: Electroanalytical methods are very functional to detect drugs in pharmaceuticals (tablets, syrups, suppositories, creams, and ointments) and biological samples. OBJECTIVE: This study is aimed to make selective, sensitive, simple, fast, and low cost electrochemical analysis of expectorant drug guaifenesin in pharmaceuticals and serum samples. METHODS: Differential pulse adsorptive stripping voltammetric method for determination of guaifenesin on a poly(acridine orange) modified glassy carbon electrode has been developed. Glassy carbon electrode was modified with electropolymerization of the acridine orange monomer for the sensitive determination of guaifenesin. Guaifenesin provided highly reproducible and welldefined irreversible oxidation peaks at +1.125 V and +1.128 V (vs. Ag/AgCl) in the selected supporting electrolyte and human serum samples, respectively. RESULTS: Under optimized conditions, linear response of peak current on the concentration of guaifenesin has been obtained in the ranges of 2.00×10-7 to 1.00×10-4 M in Britton Robinson buffer solution at pH 7.0 and 4.00×10-7 to 1.00×10-4 M in serum samples. The precision of the method was detected by intraday and inter-day repeatability studies in the supporting electrolyte and serum samples media. CONCLUSION: The analytical applicability of the proposed method exhibited satisfying determination results for guaifenesin from pharmaceutical dosage forms (syrup) and human serum samples without any pre-separation procedures.