Electrochemical properties and square-wave voltammetric determination of pravastatin.
The electrochemical reduction and adsorptive voltammetric behaviour of pravastatin have been studied by means of cyclic and square-wave voltammetry at a hanging mercury-drop electrode in electrolytes of different pH. Within the entire pH range (2.0-9.0) in Britton-Robinson buffer, pravastatin gave rise to a single voltammetric peak in the potential interval from -1.22 to -1.44 V, depending on pravastatin concentration. It was found that the reduction of pravastatin proceeds via a relatively stable intermediate, which is transformed to the final electroinactive product by a coupled chemical reaction or can be re-oxidized back to pravastatin. The rate of chemical transformation is controlled by the proton concentration. The electrode mechanism has the properties of a surface redox reaction. A sensitive analytical method for trace analysis of pravastatin based on the adsorptive stripping technique has been developed. The calibration plot was linear in the range 8x10(-8)-5x10(-7) mol L(-1). Application of the square-wave voltammetric method to determination of pravastatin in a pharmaceutical dosage form, without sample pretreatment, resulted in acceptable deviation from the stated concentration.
Nigović
Biljana
B
Faculty of Pharmacy and Biochemistry, University of Zagreb, 10000, Zagreb, Croatia. biljana@pharma.hr
D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002626:Chemistry, Pharmaceutical; D004563:Electrochemistry; D004566:Electrodes; D017035:Pravastatin / Q000032:analysis* / Q000737:chemistry*
D017035:Pravastatin