New electrochemical methods for the determination of bromhexine based on differential pulse voltammetry (DPV) and flow injection analysis with amperometric detection (FIA-ED) were developed using a glassy carbon paste electrode. Optimal supporting electrolyte for DPV measurement was methanol/Britton-Robinson buffer pH 9 (80:20, v/v).
In the case of FIA-ED, optimal conditions were as follows: detection potential +1.1 V, flow rate 1.0 cm(3) min(-1), injected volume 0.1 cm(3), and carrier solution methanol-ten times diluted B-R buffer of pH 9 (80:20, v/v). Detection limit was 2.0 x 10(-6) mol dm(-3) for DPV and 3.1 x 10(-7) mol dm(-3) for FIA-ED.
The applicability of the newly developed methods was verified by the determination of bromhexine in pharmaceutical preparations (tablets of Bromhexin-EGIS and Bromhexin 8 BC).