Square Wave Voltammetric Determination of Ropinirole HCl in Bulk, Dosage Forms and Biological Samples on Carbon Paste Electrode

Aim: Voltammetric determination for of Ropinirole HCl.

Study: We will study the behaviour of Ropinirole HCl on the carbon paste electrode. So several factors such as pH, type of pasting oil, pulse amplitude and scan rate were studied to optimize the condition for voltammetric determination of drug.

Place and Duration of Study: Microanalytical Chemistry Laboratory, Applied Organic Chemistry Department, National Research Centre, Dokki, Giza, Egypt, between August 2015 and December 2015.

Methodology: Square wave voltammetry (SWV) was employed in order to determine Ropinirole in bulk powder and plasma in a voltammetric cell containing 10 mL of 0.1 mole L-1 sulphuric acid as supporting electrolyte. After every aliquot addition, the solution was stirred for 30 s at 2000 rpm, rested for 10 s then SWV mode was ramped from +300 to +1600 mV with scan rate 100 mV s-1 and pulse amplitude 50 mV. The experiment was triplicated for every standard solution addition.

Results: A good linearity was obtained over a range of (4.96x10-6 to 3.90x10-5 mol L-1) with mean recovery and relative standard deviation (RSD) values of 99.15% and 3.7%, respectively. The lower detection (LOD) and quantification (LOQ) limits were found to be (1.48x10-6 and 4.96x10-6 mol L-1) respectively at Square wave (SWV) mode. The accuracy and precision of the method were presented with inter and intra days determinations which were within acceptable limits. The method was applied successfully for determining the active ingredients in pharmaceutical preparations with mean percentage recoveries ± RSD of 98.38±3.1 and in spiked human plasma with the mean of recoveries ± RSD, 99.56±3.63%.

Conclusion: An economic, accurate and precise electrochemical method has been developed and validated for the determination of Ropinirole HCl in bulk, dosage form and human plasma.