Adsorptive Cathodic Stripping Voltammetric Determination of Ciprofloxacin in Bulk Powder, Pharmaceutical Dosage Forms and Urine

Purpose: To investigate the electro-reduction behaviour and determination of ciprofloxacin using a hanging mercury drop electrode.
Methods: Cyclic voltammograms of ciprofloxacin recorded in Britton – Robinson buffers pH 2 – 5 exhibit a single irreversible cathodic peak. The dependence of the peak current and peak potential values on buffer (nature, pH and concentration) and accumulation conditions (time and potential) were examined and used for the quantitative analysis of ciprofloxacin in dosage forms and urine. Acetate buffer (0.08 M, pH 3.6) was selected as a supporting electrolyte for quantitative purposes by differential pulse and square wave adsorptive cathodic stripping voltammetry.
Results: A reduction wave was seen in the range of – 1.3 to – 1.5 V. These techniques were successfully validated as per ICH guidelines and comparable to US Pharmacopoeia HPLC method. The techniques was applied to the determination of ciprofloxacin in pharmaceutical formulations (i.e. precision (RSD < 1%) and accuracy (99 – 101%)), and was further extended to determine ciprofloxacin in spiked human urine with no matrix effect (i.e. LLOQ 0.01 g/ml, precision (RSD < 15%) and accuracy (85 – 115%)).
Conclusion: Validated adsorptive cathodic stripping voltammetric technique can be recommended for use in quality control and pharmacokinetics studies.

Keywords
Ciprofloxacin; Mercury electrode; Adsorptive cathodic stripping voltammetry; Pharmaceutical formulation; Urine