IJUP08 - Universidade do Porto

Pravastatin Quantification using Square-Wave Voltammetry
M. Neves 1 , S. Pereira 1 , H. Nouws 2 and C. Delerue-Matos 2
1 Departamento de Botânica, Faculdade de Ciências, Universidade do Porto, Portugal
2 REQUIMTE, Instituto Superior de Engenharia, Instituto Politécnico do Porto, Portugal
Nowadays cardiovascular diseases are the main cause of morbidity and mortality in
developed countries. Extensive epidemiologic studies reveal that hypercholesterolemia is
causally related to an increased risk in atherosclerosis and coronary heart disease. A class
of lipid-lowering drugs called statins is the most widely used in hyperlipidemic
pharmacological treatment. These compounds reduce levels of circulating atherogenic
lipoproteins by competitive inhibition of HMG-CoA redutase, the rate-limiting enzyme in
the synthesis of cholesterol. Currently, six therapeutic statins are available on the
Portuguese market: atorvastatin, fluvastatin, rosuvastatin, simvastatin, lovastatin and
pravastatin. Most statin analysis are performed by liquid-chromatography (LC) coupled
with spectrometric detectors. The main disadvantages of LC are the relatively long analysis
times, high acquisition and maintenance costs and the use of large volumes of toxic
solvents. In the present work an alternative procedure, based on square-wave voltammetry
(SWV), for the quantification of pravastatin in pharmaceutical products is proposed.
Initial studies showed that pravastatin can be oxidized at a glassy carbon electrode, with a
maximum peak current intensity at a potential of +1.3 V vs. AgCl/Ag, in a Britton-
Robinson buffer of pH 5 (I = 0.3 mol/L). Several parameters of the SWV method were
optimized, resulting in the following conditions: frequency = 90 Hz, step potential = 5.25
mV and step amplitude = 40.05 mV. The method was validated by assessing the linear
range between peak current intensity and pravastatin concentration, limits of detection and
quantification, repeatability, intermediated precision and accuracy.
The developed methodology was applied in the quantification of pravastatin in a
pharmaceutical product. It could be a useful alternative to the established methods for this
purpose since it provides high sample rates at reduce costs with a low pollution rate.
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